Android build v1.1.15

AGENTS.md

@@ -34,6 +34,7 @@
 - IWT2 rendering can use a 2D canvas/game runtime, but renderer objects must not become the source of truth for saveable gameplay state.
 - IWT2 needs continuous movement input: left analog stick on AYN Thor and WASD on keyboard. Do not rely only on existing menu-style navigation actions for arena movement.
 - IWT2 menus, dialogs, inventory, collection log, pause overlays, and game-select screen must still follow controller navigation requirements.
+- IWT2 boss mechanics and indicators must be modular. Add reusable hit-shape, damage/status, telegraph/indicator, hazard, and marker primitives under `src/modes/iwt2/sim/` or `src/modes/iwt2/render/` instead of hardcoding boss-specific rules in Phaser scenes. Boss AI may compose these primitives, but renderer code should draw sim-owned indicators generically.
 - First IWT2 boss conversion target: Bulldrome. Bulldrome should have normal melee tank damage, a charge across the arena that damages and knocks down/stuns hit players for 0.75 seconds, and every 3rd charge should be followed by an AoE ground slam around the boss that also damages and knocks down/stuns hit players for 0.75 seconds.
 - IWT2 starter party fantasy: player-controlled healer plus visible party members moving in the arena. Paladin tank holds aggro; ranger fires arrows; mage fires fireballs; rogue flanks; warrior fights in melee. Each class should have a distinct icon and color scheme.
 

android/app/build.gradle

@@ -7,8 +7,8 @@ android {
         applicationId "com.warren.iwanttoheal"
         minSdkVersion rootProject.ext.minSdkVersion
         targetSdkVersion rootProject.ext.targetSdkVersion
-        versionCode 93
-        versionName "1.1.14"
+        versionCode 94
+        versionName "1.1.15"
         testInstrumentationRunner "androidx.test.runner.AndroidJUnitRunner"
         aaptOptions {
              // Files and dirs to omit from the packaged assets dir, modified to accommodate modern web apps.

package-lock.json

@@ -10,6 +10,7 @@
       "dependencies": {
         "@capacitor/android": "^8.4.0",
         "@capacitor/core": "^8.4.0",
+        "phaser": "^4.2.0",
         "react": "^19.2.6",
         "react-dom": "^19.2.6"
       },
@@ -2030,6 +2031,12 @@
         "node": ">=0.10.0"
       }
     },
+    "node_modules/eventemitter3": {
+      "version": "5.0.4",
+      "resolved": "https://registry.npmjs.org/eventemitter3/-/eventemitter3-5.0.4.tgz",
+      "integrity": "sha512-mlsTRyGaPBjPedk6Bvw+aqbsXDtoAyAzm5MO7JgU+yVRyMQ5O8bD4Kcci7BS85f93veegeCPkL8R4GLClnjLFw==",
+      "license": "MIT"
+    },
     "node_modules/fast-deep-equal": {
       "version": "3.1.3",
       "resolved": "https://registry.npmjs.org/fast-deep-equal/-/fast-deep-equal-3.1.3.tgz",
@@ -2969,6 +2976,15 @@
       "dev": true,
       "license": "MIT"
     },
+    "node_modules/phaser": {
+      "version": "4.2.0",
+      "resolved": "https://registry.npmjs.org/phaser/-/phaser-4.2.0.tgz",
+      "integrity": "sha512-9nSQZs4CJ9+V96i2mRC3BBStBcsQWGJJBRpdFYSbpL40/i/QM+wLofaCYMsxNyDk8WJOlHGZUh3uVRKa7lj6yg==",
+      "license": "MIT",
+      "dependencies": {
+        "eventemitter3": "^5.0.4"
+      }
+    },
     "node_modules/picocolors": {
       "version": "1.1.1",
       "resolved": "https://registry.npmjs.org/picocolors/-/picocolors-1.1.1.tgz",

package.json

@@ -28,6 +28,7 @@
   "dependencies": {
     "@capacitor/android": "^8.4.0",
     "@capacitor/core": "^8.4.0",
+    "phaser": "^4.2.0",
     "react": "^19.2.6",
     "react-dom": "^19.2.6"
   },

server/admin.mjs

@@ -1,4 +1,4 @@
-import { createReadStream, existsSync, mkdirSync, statSync, writeFileSync } from 'node:fs'
+import { createReadStream, existsSync, mkdirSync, readdirSync, readFileSync, statSync, writeFileSync } from 'node:fs'
 import { createServer } from 'node:http'
 import { randomBytes } from 'node:crypto'
 import { extname, resolve, sep } from 'node:path'
@@ -10,6 +10,7 @@ const port = Number(process.env.ADMIN_PORT ?? 4174)
 const databasePath = fileURLToPath(new URL('../data/game.db', import.meta.url))
 const distPath = fileURLToPath(new URL('../dist', import.meta.url))
 const adminOverridesPath = fileURLToPath(new URL('../db/admin-overrides.sql', import.meta.url))
+const iwt2BalanceOverridesPath = fileURLToPath(new URL('../src/modes/iwt2/content/balanceOverrides.ts', import.meta.url))
 const bossImageDirectory = fileURLToPath(new URL('../data/uploads/bosses/', import.meta.url))
 const itemImageDirectory = fileURLToPath(new URL('../data/uploads/items/', import.meta.url))
 const dungeonImageDirectory = fileURLToPath(new URL('../data/uploads/dungeons/', import.meta.url))
@@ -248,6 +249,89 @@ function saveDungeonImage(database, dungeonId, payload) {
   return imageUrl
 }
 
+function readIwt2BalanceOverrides() {
+  if (!existsSync(iwt2BalanceOverridesPath)) return { bosses: {} }
+  const source = readFileSync(iwt2BalanceOverridesPath, 'utf8')
+  const exportIndex = source.indexOf('IWT2_BALANCE_OVERRIDES')
+  const objectStart = source.indexOf('{', exportIndex)
+  const objectEnd = source.lastIndexOf('}')
+  if (exportIndex < 0 || objectStart < 0 || objectEnd <= objectStart) return { bosses: {} }
+  try {
+    const parsed = JSON.parse(source.slice(objectStart, objectEnd + 1))
+    return sanitizeIwt2BalanceOverrides(parsed)
+  } catch {
+    return { bosses: {} }
+  }
+}
+
+function sanitizeIwt2BalanceOverrides(value) {
+  const overrides = { bosses: {} }
+  const bosses = value && typeof value === 'object' && value.bosses && typeof value.bosses === 'object'
+    ? value.bosses
+    : {}
+  for (const bossId of ['bulldrome', 'yian-kut-ku']) {
+    const boss = bosses[bossId]
+    if (!boss || typeof boss !== 'object') continue
+    const nextBoss = {}
+    if (Number.isFinite(Number(boss.maxHealth))) nextBoss.maxHealth = Math.max(1, Math.round(Number(boss.maxHealth)))
+    if (bossId === 'yian-kut-ku' && Number.isFinite(Number(boss.birdHealth))) {
+      nextBoss.birdHealth = Math.max(1, Math.round(Number(boss.birdHealth)))
+    }
+    if (Object.keys(nextBoss).length > 0) overrides.bosses[bossId] = nextBoss
+  }
+  return overrides
+}
+
+function writeIwt2BalanceOverrides(overrides) {
+  const source = [
+    "import type { Iwt2BalanceOverrides } from './bosses'",
+    '',
+    '// Generated by local admin panel. Commit this file with intended IWT2 balance changes.',
+    `export const IWT2_BALANCE_OVERRIDES: Iwt2BalanceOverrides = ${JSON.stringify(sanitizeIwt2BalanceOverrides(overrides), null, 2)}`,
+    '',
+  ].join('\n')
+  writeFileSync(iwt2BalanceOverridesPath, source, { mode: 0o644 })
+}
+
+function updateIwt2EntityHp(entityId, payload) {
+  const maxHealth = Number(payload.maxHealth)
+  if (!Number.isFinite(maxHealth) || maxHealth <= 0) throw new Error('HP must be greater than zero.')
+  const roundedHealth = Math.round(maxHealth)
+  const overrides = readIwt2BalanceOverrides()
+  const bosses = { ...(overrides.bosses ?? {}) }
+  if (entityId === 'bulldrome' || entityId === 'yian-kut-ku') {
+    bosses[entityId] = {
+      ...(bosses[entityId] ?? {}),
+      maxHealth: roundedHealth,
+    }
+  } else if (entityId === 'yian-kut-ku:yian-bird' || entityId === 'yian-bird') {
+    bosses['yian-kut-ku'] = {
+      ...(bosses['yian-kut-ku'] ?? {}),
+      birdHealth: roundedHealth,
+    }
+  } else {
+    throw new Error('IWT2 entity not found.')
+  }
+  const nextOverrides = sanitizeIwt2BalanceOverrides({ bosses })
+  writeIwt2BalanceOverrides(nextOverrides)
+  return nextOverrides
+}
+
+function listIwt2BossAssets() {
+  if (!existsSync(bossImageDirectory)) return []
+  return readdirSync(bossImageDirectory, { withFileTypes: true })
+    .filter((entry) => entry.isFile() && bossImageContentTypes[extname(entry.name).toLowerCase()])
+    .map((entry) => {
+      const imagePath = resolve(bossImageDirectory, entry.name)
+      return {
+        filename: entry.name,
+        size: statSync(imagePath).size,
+        url: `/api/boss-images/${entry.name}`,
+      }
+    })
+    .sort((a, b) => a.filename.localeCompare(b.filename))
+}
+
 function sendFile(response, filePath) {
   const contentTypes = {
     '.css': 'text/css; charset=utf-8',
@@ -308,6 +392,22 @@ const server = createServer(async (request, response) => {
       return
     }
 
+    if (request.url === '/api/admin/iwt2/data' && request.method === 'GET') {
+      sendJson(response, 200, {
+        balanceOverrides: readIwt2BalanceOverrides(),
+        bossAssets: listIwt2BossAssets(),
+      })
+      return
+    }
+
+    const iwt2HpMatch = request.url.match(/^\/api\/admin\/iwt2\/entities\/([^/]+)\/hp$/)
+    if (iwt2HpMatch && request.method === 'PUT') {
+      const payload = await readJson(request)
+      const balanceOverrides = updateIwt2EntityHp(decodeURIComponent(iwt2HpMatch[1]), payload)
+      sendJson(response, 200, { ok: true, balanceOverrides })
+      return
+    }
+
     if (!existsSync(databasePath)) {
       sendJson(response, 503, { error: 'Database missing. Run npm run db:init.' })
       return

src/components/AdminScreen.tsx

@@ -1,5 +1,11 @@
 import { useEffect, useState } from 'react'
 import type { CSSProperties, Dispatch, SetStateAction } from 'react'
+import {
+  IWT2_BOSS_METADATA,
+  type Iwt2BalanceOverrides,
+  type Iwt2BossId,
+  type Iwt2BossMetadata,
+} from '../modes/iwt2/content/bosses'
 
 type AdminItem = {
   id: number
@@ -130,7 +136,38 @@ type AdminData = {
   classes: AdminClass[]
 }
 
-type AdminTab = 'items' | 'dungeons' | 'encounters' | 'loot' | 'crafting' | 'upgrades' | 'classes'
+type Iwt2AdminAsset = {
+  filename: string
+  size: number
+  url: string
+}
+
+type Iwt2AdminData = {
+  balanceOverrides: Iwt2BalanceOverrides
+  bossAssets: Iwt2AdminAsset[]
+}
+
+type Iwt2AdminAttack = {
+  name: string
+  frequency: string
+  damage: string
+  details: string
+}
+
+type Iwt2AdminEntityRow = {
+  id: string
+  bossId: Iwt2BossId
+  kind: 'boss' | 'mob'
+  name: string
+  slug: string
+  icon: string
+  color: string
+  maxHealth: number
+  attacks: Iwt2AdminAttack[]
+  assets: Iwt2AdminAsset[]
+}
+
+type AdminTab = 'items' | 'dungeons' | 'encounters' | 'loot' | 'crafting' | 'upgrades' | 'classes' | 'iwt2'
 type SavingState = Record<string, boolean>
 type SetData = Dispatch<SetStateAction<AdminData | null>>
 type SetSaving = Dispatch<SetStateAction<SavingState>>
@@ -144,6 +181,7 @@ const tabs: { id: AdminTab; label: string }[] = [
   { id: 'crafting', label: 'Crafting' },
   { id: 'upgrades', label: 'Upgrades' },
   { id: 'classes', label: 'Classes' },
+  { id: 'iwt2', label: 'IWT2' },
 ]
 
 async function fetchJson<T>(url: string, init?: RequestInit): Promise<T> {
@@ -189,6 +227,7 @@ export function AdminScreen({ onBack }: { onBack: () => void }) {
       {tab === 'crafting' && <CraftingTab data={data} setData={setData} setSaving={setSaving} saving={saving} />}
       {tab === 'upgrades' && <UpgradesTab data={data} setData={setData} setSaving={setSaving} saving={saving} />}
       {tab === 'classes' && <ClassesTab data={data} />}
+      {tab === 'iwt2' && <Iwt2AdminTab />}
     </section>
   )
 }
@@ -1155,6 +1194,196 @@ function ClassesTab({ data }: { data: AdminData }) {
   )
 }
 
+function Iwt2AdminTab() {
+  const [metadata, setMetadata] = useState<Record<Iwt2BossId, Iwt2BossMetadata>>(IWT2_BOSS_METADATA)
+  const [adminData, setAdminData] = useState<Iwt2AdminData | null>(null)
+  const [error, setError] = useState('')
+  const [selectedEntityId, setSelectedEntityId] = useState<string>('bulldrome')
+  const [draftHp, setDraftHp] = useState<Record<string, string>>({})
+  const [saving, setSaving] = useState<Record<string, boolean>>({})
+
+  useEffect(() => {
+    fetchJson<Iwt2AdminData>(`${API}/iwt2/data`)
+      .then((result) => {
+        setAdminData(result)
+        setMetadata(applyIwt2AdminOverrides(IWT2_BOSS_METADATA, result.balanceOverrides))
+      })
+      .catch((e: unknown) => {
+        setError(e instanceof Error ? e.message : 'Failed to load IWT2 admin data')
+        setAdminData({ balanceOverrides: { bosses: {} }, bossAssets: [] })
+      })
+  }, [])
+
+  const rows = createIwt2AdminRows(metadata, adminData?.bossAssets ?? [])
+  const selectedRow = rows.find((row) => row.id === selectedEntityId) ?? rows[0]
+
+  async function saveHp(row: Iwt2AdminEntityRow) {
+    const value = Number(draftHp[row.id] ?? row.maxHealth)
+    if (!Number.isFinite(value) || value <= 0) {
+      alert('HP must be greater than zero.')
+      return
+    }
+    const nextHealth = Math.round(value)
+    setSaving((prev) => ({ ...prev, [row.id]: true }))
+    try {
+      await fetchJson(`${API}/iwt2/entities/${encodeURIComponent(row.id)}/hp`, jsonRequest('PUT', { maxHealth: nextHealth }))
+      setMetadata((current) => {
+        const boss = current[row.bossId]
+        return {
+          ...current,
+          [row.bossId]: row.kind === 'boss'
+            ? { ...boss, maxHealth: nextHealth }
+            : { ...boss, birdHealth: nextHealth },
+        }
+      })
+      setDraftHp((prev) => {
+        const next = { ...prev }
+        delete next[row.id]
+        return next
+      })
+    } catch (e: unknown) {
+      alert(e instanceof Error ? e.message : 'Save failed')
+    } finally {
+      setSaving((prev) => ({ ...prev, [row.id]: false }))
+    }
+  }
+
+  return (
+    <div className="admin-panel iwt2-admin-panel">
+      {error && <p className="error-message">{error}</p>}
+      <div className="iwt2-admin-summary">
+        <span>{rows.length} mobs / bosses</span>
+        <span>{adminData?.bossAssets.length ?? 0} uploaded boss assets</span>
+        <span>HP edits write to IWT2 balance overrides</span>
+      </div>
+      <div className="iwt2-admin-layout">
+        <aside className="iwt2-admin-entity-list" aria-label="IWT2 mobs and bosses">
+          {rows.map((row) => (
+            <button
+              className={selectedRow?.id === row.id ? 'active' : ''}
+              key={row.id}
+              onClick={() => setSelectedEntityId(row.id)}
+              type="button"
+            >
+              <span className="iwt2-admin-token" style={{ '--iwt2-entity-color': row.color } as CSSProperties}>{row.icon}</span>
+              <span>
+                <strong>{row.name}</strong>
+                <small>{row.kind} · {row.maxHealth} hp · {row.attacks.length} attacks</small>
+              </span>
+            </button>
+          ))}
+        </aside>
+        {selectedRow && (
+          <Iwt2AdminDetail
+            draftHp={draftHp}
+            row={selectedRow}
+            saveHp={saveHp}
+            saving={saving}
+            setDraftHp={setDraftHp}
+          />
+        )}
+      </div>
+    </div>
+  )
+}
+
+function Iwt2AdminDetail({
+  draftHp,
+  row,
+  saveHp,
+  saving,
+  setDraftHp,
+}: {
+  draftHp: Record<string, string>
+  row: Iwt2AdminEntityRow
+  saveHp: (row: Iwt2AdminEntityRow) => void
+  saving: Record<string, boolean>
+  setDraftHp: Dispatch<SetStateAction<Record<string, string>>>
+}) {
+  const value = draftHp[row.id] ?? String(row.maxHealth)
+  const changed = Number(value) !== row.maxHealth
+
+  return (
+    <section className="iwt2-admin-detail">
+      <header className="iwt2-admin-detail-hero">
+        <span className="iwt2-admin-token" style={{ '--iwt2-entity-color': row.color } as CSSProperties}>{row.icon}</span>
+        <div>
+          <p className="eyebrow">{row.kind}</p>
+          <h2>{row.name}</h2>
+          <small>{row.slug} · source boss: {row.bossId}</small>
+        </div>
+      </header>
+
+      <label className="iwt2-admin-hp">
+        HP
+        <input
+          min="1"
+          step="1"
+          type="number"
+          value={value}
+          onChange={(event) => setDraftHp((prev) => ({ ...prev, [row.id]: event.target.value }))}
+        />
+        <button
+          className="primary-button"
+          disabled={!changed || saving[row.id]}
+          onClick={() => saveHp(row)}
+          type="button"
+        >
+          {saving[row.id] ? 'Saving...' : 'Save HP'}
+        </button>
+      </label>
+
+      <section className="iwt2-admin-section">
+        <div className="iwt2-admin-section-heading">
+          <h3>Assets</h3>
+          <span>{row.assets.length} uploaded</span>
+        </div>
+        <div className="iwt2-admin-assets">
+          <div className="iwt2-admin-swatch" style={{ '--iwt2-entity-color': row.color } as CSSProperties}>
+            <span>{row.icon}</span>
+            <strong>Runtime Token</strong>
+            <small>Icon and color used by current arena renderer.</small>
+          </div>
+          {row.assets.length > 0 ? row.assets.map((asset) => {
+            const label = iwt2AssetLabel(asset.filename)
+            return (
+              <a href={asset.url} key={asset.filename} target="_blank" rel="noreferrer">
+                <img src={asset.url} alt={`${row.name} ${label}`} />
+                <strong>{label}</strong>
+                <small>{asset.filename}</small>
+              </a>
+            )
+          }) : (
+            <p className="admin-item-desc">No uploaded raster asset matched. Runtime uses shape, icon, and color.</p>
+          )}
+        </div>
+      </section>
+
+      <section className="iwt2-admin-section">
+        <div className="iwt2-admin-section-heading">
+          <h3>Attacks</h3>
+          <span>{row.attacks.length} mechanics</span>
+        </div>
+        <div className="iwt2-admin-attacks">
+          <div className="iwt2-admin-attack-head">
+            <span>Attack</span>
+            <span>Frequency</span>
+            <span>Damage</span>
+          </div>
+          {row.attacks.map((attack) => (
+            <div className="iwt2-admin-attack-row" key={`${row.id}-${attack.name}`}>
+              <strong>{attack.name}</strong>
+              <span>{attack.frequency}</span>
+              <span>{attack.damage}</span>
+              <small>{attack.details}</small>
+            </div>
+          ))}
+        </div>
+      </section>
+    </section>
+  )
+}
+
 function jsonRequest(method: 'POST' | 'PUT', body: unknown): RequestInit {
   return {
     method,
@@ -1163,6 +1392,136 @@ function jsonRequest(method: 'POST' | 'PUT', body: unknown): RequestInit {
   }
 }
 
+function applyIwt2AdminOverrides(
+  metadata: Record<Iwt2BossId, Iwt2BossMetadata>,
+  overrides: Iwt2BalanceOverrides,
+): Record<Iwt2BossId, Iwt2BossMetadata> {
+  return {
+    bulldrome: {
+      ...metadata.bulldrome,
+      ...overrides.bosses?.bulldrome,
+    },
+    'yian-kut-ku': {
+      ...metadata['yian-kut-ku'],
+      ...overrides.bosses?.['yian-kut-ku'],
+    },
+  }
+}
+
+function createIwt2AdminRows(
+  metadata: Record<Iwt2BossId, Iwt2BossMetadata>,
+  bossAssets: Iwt2AdminAsset[],
+): Iwt2AdminEntityRow[] {
+  const bosses = Object.values(metadata).map((boss): Iwt2AdminEntityRow => ({
+    assets: assetsForIwt2Boss(boss.id, bossAssets),
+    attacks: bossAttacks(boss),
+    bossId: boss.id,
+    color: boss.color,
+    icon: boss.icon,
+    id: boss.id,
+    kind: 'boss',
+    maxHealth: boss.maxHealth,
+    name: boss.name,
+    slug: boss.id,
+  }))
+  const yian = metadata['yian-kut-ku']
+  if (!yian.birdHealth) return bosses
+  return [
+    ...bosses,
+    {
+      assets: [],
+      attacks: yianBirdAttacks(yian),
+      bossId: yian.id,
+      color: '#f0b84f',
+      icon: 'v',
+      id: `${yian.id}:yian-bird`,
+      kind: 'mob',
+      maxHealth: yian.birdHealth,
+      name: 'Yian Kut Ku Hatchling',
+      slug: 'yian-bird',
+    },
+  ]
+}
+
+function bossAttacks(boss: Iwt2BossMetadata): Iwt2AdminAttack[] {
+  const attacks: Iwt2AdminAttack[] = [{
+    damage: `${boss.meleeDamage}`,
+    details: `Range ${boss.meleeRange}px`,
+    frequency: `${formatSeconds(boss.meleeCooldown)} cooldown`,
+    name: 'Melee',
+  }]
+  if (boss.chargeCooldown > 0) {
+    attacks.push({
+      damage: `${boss.chargeDamage}`,
+      details: `${formatSeconds(boss.chargeWindup)} windup, ${formatSeconds(boss.chargeStunSeconds)} stun / knockdown`,
+      frequency: `${formatSeconds(boss.chargeCooldown)} cooldown`,
+      name: 'Charge',
+    })
+  }
+  if (boss.slamDamage > 0) {
+    attacks.push({
+      damage: `${boss.slamDamage}`,
+      details: `${boss.slamRadius}px radius, ${formatSeconds(boss.slamStunSeconds)} stun / knockdown`,
+      frequency: 'Every 3rd charge',
+      name: 'Ground Slam',
+    })
+  }
+  if (boss.fireballCooldown && boss.fireballDamage) {
+    attacks.push({
+      damage: `${boss.fireballDamage} hit + ${boss.firePuddleDamage ?? 0}/tick puddle`,
+      details: `${boss.firePuddleRadius ?? 0}px puddle for ${formatSeconds(boss.firePuddleSeconds ?? 0)}`,
+      frequency: `${formatSeconds(boss.fireballCooldown)} cooldown`,
+      name: 'Fireball',
+    })
+  }
+  if (boss.birdWaveThresholds?.length) {
+    attacks.push({
+      damage: `${boss.birdContactDamage ?? 0} contact`,
+      details: `${boss.birdWaveThresholds.map((threshold) => `${Math.round(threshold * 100)}%`).join(', ')} HP thresholds`,
+      frequency: 'Health threshold',
+      name: 'Bird Wave',
+    })
+  }
+  return attacks
+}
+
+function yianBirdAttacks(boss: Iwt2BossMetadata): Iwt2AdminAttack[] {
+  return [
+    {
+      damage: `${boss.birdContactDamage ?? 0}`,
+      details: `Contact radius ${boss.birdRadius ?? 0}px`,
+      frequency: '1.15s cooldown',
+      name: 'Peck',
+    },
+    {
+      damage: '10',
+      details: `${formatSeconds(boss.birdFlightWindup ?? 0)} windup, ${formatSeconds(boss.birdStunSeconds ?? 0)} stun`,
+      frequency: `${formatSeconds(boss.birdFlightCooldown ?? 0)} cooldown`,
+      name: 'Flight Lane',
+    },
+  ]
+}
+
+function assetsForIwt2Boss(bossId: Iwt2BossId, bossAssets: Iwt2AdminAsset[]): Iwt2AdminAsset[] {
+  const terms = bossId.split('-').filter((part) => part.length > 2)
+  return bossAssets.filter((asset) => {
+    const filename = asset.filename.toLowerCase()
+    return filename.includes(bossId) || terms.some((term) => filename.includes(term))
+  })
+}
+
+function iwt2AssetLabel(filename: string) {
+  const normalized = filename.toLowerCase()
+  if (normalized.includes('approach')) return 'Approach Illustration'
+  if (normalized.includes('guardians')) return 'Party Encounter Art'
+  if (normalized.includes('boss')) return 'Boss Portrait'
+  return 'Primary Boss Art'
+}
+
+function formatSeconds(value: number) {
+  return `${Number.isInteger(value) ? value.toFixed(0) : value.toFixed(2).replace(/0$/, '')}s`
+}
+
 function fileToDataUrl(file: File) {
   return new Promise<string>((resolve, reject) => {
     const reader = new FileReader()

src/components/PartyFrames.tsx

@@ -109,7 +109,7 @@ export const PartyMemberFrame = memo(function PartyMemberFrame({
   ].filter(Boolean).join(' ')
   const action = targetBinding ? {
     binding: targetBinding,
-    iconStyle: controllerIconStyle ?? 'xbox',
+    iconStyle: controllerIconStyle ?? 'playstation',
   } : null
 
   return (

src/input.tsx

@@ -13,6 +13,10 @@ import { Capacitor } from '@capacitor/core'
 
 export type InputDevice = 'pc' | 'controller'
 export type ControllerIconStyle = 'xbox' | 'playstation' | 'nintendo'
+export type MovementVector = {
+  x: number
+  y: number
+}
 
 export const INPUT_ACTIONS = [
   'navigateUp',
@@ -131,7 +135,7 @@ const PREFERENCES_STORAGE_KEY = 'ashen-halls-input-preferences-v1'
 const GAME_ACTION_EVENT = 'ashen-halls-game-action'
 const NATIVE_CONTROLLER_EVENT = 'ashen-halls-native-controller'
 const FOCUSABLE_SELECTOR = 'button:not(:disabled):not([data-controller-nav="skip"]), input:not(:disabled):not([data-controller-nav="skip"]), select:not(:disabled):not([data-controller-nav="skip"]), textarea:not(:disabled):not([data-controller-nav="skip"]), [tabindex]:not([tabindex="-1"]):not([data-controller-nav="skip"])'
-const MAIN_CONTENT_SELECTOR = '.auth-shell, .menu-screen, .content-screen, .dungeon-run-screen, .dual-bottom-display'
+const MAIN_CONTENT_SELECTOR = '.auth-shell, .menu-screen, .content-screen, .dungeon-run-screen, .dual-bottom-display, .iwt2-bottom-display'
 const HEADER_CONTENT_SELECTOR = '.app-header'
 const GAMEPAD_COMBAT_POLL_MS = 1000 / 60
 const GAMEPAD_MENU_POLL_MS = 1000 / 30
@@ -235,13 +239,13 @@ function loadPreferences() {
       combatTouchLocked?: boolean
     }
     return {
-      controllerIconStyle: saved.controllerIconStyle ?? 'xbox',
+      controllerIconStyle: saved.controllerIconStyle ?? 'playstation',
       directPartyTargeting: saved.directPartyTargeting ?? false,
       combatTouchLocked: saved.combatTouchLocked ?? Capacitor.isNativePlatform(),
     }
   } catch {
     return {
-      controllerIconStyle: 'xbox' as ControllerIconStyle,
+      controllerIconStyle: 'playstation' as ControllerIconStyle,
       directPartyTargeting: false,
       combatTouchLocked: Capacitor.isNativePlatform(),
     }
@@ -530,6 +534,10 @@ function isCombatActive() {
   return Boolean(document.querySelector('[data-combat-active="true"]'))
 }
 
+function hasContinuousMovementActive() {
+  return Boolean(document.querySelector('[data-continuous-movement-active="true"]'))
+}
+
 function firstConnectedGamepad() {
   return Array.from(navigator.getGamepads?.() ?? []).find(Boolean) ?? null
 }
@@ -686,6 +694,12 @@ export function InputProvider({ children }: { children: ReactNode }) {
       document.querySelector('[data-combat-active="true"]'),
     )
     const uiOverlay = hasUiOverlay()
+    if (
+      combatActive
+      && !uiOverlay
+      && hasContinuousMovementActive()
+      && (token.startsWith('Axis0') || token.startsWith('Axis1'))
+    ) return
     const uiPriority = [
       'navigateUp',
       'navigateDown',
@@ -1046,6 +1060,74 @@ export function InputProvider({ children }: { children: ReactNode }) {
   )
 }
 
+function normalizedVector(x: number, y: number): MovementVector {
+  const magnitude = Math.hypot(x, y)
+  if (magnitude <= 1) return { x, y }
+  return { x: x / magnitude, y: y / magnitude }
+}
+
+function applyStickDeadzone(x: number, y: number, deadzone = 0.18): MovementVector {
+  const magnitude = Math.hypot(x, y)
+  if (magnitude < deadzone) return { x: 0, y: 0 }
+  const scaled = Math.min(1, (magnitude - deadzone) / (1 - deadzone))
+  return {
+    x: (x / magnitude) * scaled,
+    y: (y / magnitude) * scaled,
+  }
+}
+
+export function useMovementVectorRef(enabled = true) {
+  const movementRef = useRef<MovementVector>({ x: 0, y: 0 })
+
+  useEffect(() => {
+    if (!enabled) {
+      movementRef.current = { x: 0, y: 0 }
+      return undefined
+    }
+
+    let frame = 0
+    const pressedKeys = new Set<string>()
+    const keyboardVector = () => normalizedVector(
+      (pressedKeys.has('KeyD') ? 1 : 0) - (pressedKeys.has('KeyA') ? 1 : 0),
+      (pressedKeys.has('KeyS') ? 1 : 0) - (pressedKeys.has('KeyW') ? 1 : 0),
+    )
+    const updateMovement = () => {
+      const gamepad = firstConnectedGamepad()
+      const stick = gamepad ? applyStickDeadzone(gamepad.axes[0] ?? 0, gamepad.axes[1] ?? 0) : { x: 0, y: 0 }
+      const keyboard = keyboardVector()
+      movementRef.current = Math.hypot(stick.x, stick.y) > 0
+        ? stick
+        : keyboard
+      frame = window.requestAnimationFrame(updateMovement)
+    }
+    const onKeyDown = (event: KeyboardEvent) => {
+      if (isTextInput(document.activeElement)) return
+      if (!['KeyW', 'KeyA', 'KeyS', 'KeyD'].includes(event.code)) return
+      pressedKeys.add(event.code)
+      document.documentElement.dataset.inputDevice = 'pc'
+      event.preventDefault()
+    }
+    const onKeyUp = (event: KeyboardEvent) => {
+      if (!['KeyW', 'KeyA', 'KeyS', 'KeyD'].includes(event.code)) return
+      pressedKeys.delete(event.code)
+      event.preventDefault()
+    }
+
+    window.addEventListener('keydown', onKeyDown)
+    window.addEventListener('keyup', onKeyUp)
+    frame = window.requestAnimationFrame(updateMovement)
+
+    return () => {
+      window.cancelAnimationFrame(frame)
+      window.removeEventListener('keydown', onKeyDown)
+      window.removeEventListener('keyup', onKeyUp)
+      movementRef.current = { x: 0, y: 0 }
+    }
+  }, [enabled])
+
+  return movementRef
+}
+
 export function useInput() {
   const context = useContext(InputContext)
   if (!context) throw new Error('useInput must be used inside InputProvider')

src/main.tsx

@@ -2,13 +2,21 @@ import { StrictMode } from 'react'
 import { createRoot } from 'react-dom/client'
 import { Capacitor } from '@capacitor/core'
 import './index.css'
+import './App.css'
 import App from './App.tsx'
 import { InputProvider } from './input.tsx'
 import { DualScreenBottomDisplay, DualScreenProvider, DualScreenStartupPrompt } from './dualScreen.tsx'
+import { Iwt2BottomDisplay } from './modes/iwt2/Iwt2BottomDisplay.tsx'
+
+const displayMode = new URLSearchParams(window.location.search).get('display')
 
 createRoot(document.getElementById('root')!).render(
   <StrictMode>
-    {new URLSearchParams(window.location.search).get('display') === 'bottom' ? (
+    {displayMode === 'iwt2-bottom' ? (
+      <InputProvider>
+        <Iwt2BottomDisplay />
+      </InputProvider>
+    ) : displayMode === 'bottom' ? (
       <InputProvider>
         <DualScreenBottomDisplay />
       </InputProvider>

src/modes/iwt2/IWantToHeal2App.tsx

@@ -0,0 +1,243 @@
+import { useEffect, useState } from 'react'
+import { useGameAction } from '../../input'
+import { BossArenaScreen } from './screens/BossArenaScreen'
+import {
+  Iwt2CloudSaveScreen,
+  Iwt2CustomizeCharacterScreen,
+  Iwt2DungeonsScreen,
+  Iwt2HunterProfileScreen,
+  Iwt2ModePlaceholderScreen,
+  Iwt2SettingsScreen,
+} from './screens/Iwt2ShellScreens'
+import {
+  loadIwt2Save,
+  writeIwt2Save,
+  type Iwt2Save,
+} from './save/iwt2Repository'
+import type { Iwt2BossId } from './content/bosses'
+
+type Iwt2Screen =
+  | 'menu'
+  | 'arena'
+  | 'cloud-save'
+  | 'dungeons'
+  | 'raids'
+  | 'roguelike'
+  | 'pvp'
+  | 'hunter-profile'
+  | 'customize-character'
+  | 'settings'
+
+const IWT2_MENU_COLUMNS = 4
+
+const MENU_ITEMS: Array<{
+  screen: Iwt2Screen
+  title: string
+  description: string
+  glyph: string
+}> = [
+  {
+    screen: 'cloud-save',
+    title: 'Cloud Save',
+    description: 'Account sync shell for IWT2 progression and local save status.',
+    glyph: 'C',
+  },
+  {
+    screen: 'dungeons',
+    title: 'Dungeons',
+    description: 'Queue into IWT2 boss arenas. Bulldrome and Yian Kut Ku are playable slices.',
+    glyph: 'D',
+  },
+  {
+    screen: 'raids',
+    title: 'Raids',
+    description: 'Large-party encounter shell for future multi-group boss fights.',
+    glyph: 'R',
+  },
+  {
+    screen: 'roguelike',
+    title: 'Roguelike',
+    description: 'Run-based IWT2 progression shell for room chains and reward drafts.',
+    glyph: 'G',
+  },
+  {
+    screen: 'pvp',
+    title: 'PvP',
+    description: 'Competitive healing shell with controller targeting preserved.',
+    glyph: 'P',
+  },
+  {
+    screen: 'hunter-profile',
+    title: 'Hunter Profile',
+    description: 'IWT2 level, inventory summary, and collection log.',
+    glyph: 'H',
+  },
+  {
+    screen: 'customize-character',
+    title: 'Customize Character',
+    description: 'IWT2-only character identity and cosmetic setup shell.',
+    glyph: 'K',
+  },
+  {
+    screen: 'settings',
+    title: 'Settings',
+    description: 'IWT2 targeting preference and controller icon style.',
+    glyph: 'S',
+  },
+]
+
+export function IWantToHeal2App({ onBackToGameSelect }: { onBackToGameSelect: () => void }) {
+  const [screen, setScreen] = useState<Iwt2Screen>('menu')
+  const [save, setSave] = useState<Iwt2Save>(loadIwt2Save)
+  const [selectedIndex, setSelectedIndex] = useState(0)
+  const [selectedBossId, setSelectedBossId] = useState<Iwt2BossId>('bulldrome')
+
+  useEffect(() => {
+    writeIwt2Save(save)
+  }, [save])
+
+  useGameAction((action, device) => {
+    if (screen !== 'menu' || device !== 'controller') return
+    if (action === 'back') {
+      onBackToGameSelect()
+      return
+    }
+    if (action === 'confirm') {
+      setScreen(MENU_ITEMS[selectedIndex].screen)
+      return
+    }
+    if (action === 'navigateUp' || action === 'navigateLeft') {
+      const offset = action === 'navigateUp' ? IWT2_MENU_COLUMNS : 1
+      setSelectedIndex((current) => Math.max(0, current - offset))
+    } else if (action === 'navigateDown' || action === 'navigateRight') {
+      const offset = action === 'navigateDown' ? IWT2_MENU_COLUMNS : 1
+      setSelectedIndex((current) => Math.min(MENU_ITEMS.length - 1, current + offset))
+    }
+  })
+
+  if (screen === 'arena') {
+    return (
+      <BossArenaScreen
+        bossId={selectedBossId}
+        save={save}
+        onBack={() => setScreen('menu')}
+        onSaveUpdated={setSave}
+      />
+    )
+  }
+
+  if (screen === 'dungeons') {
+    return (
+      <main className="game-shell iwt2-shell">
+        <Iwt2Header save={save} onBackToGameSelect={onBackToGameSelect} />
+        <Iwt2DungeonsScreen
+          onBack={() => setScreen('menu')}
+          onOpenBoss={(bossId) => {
+            setSelectedBossId(bossId)
+            setScreen('arena')
+          }}
+        />
+      </main>
+    )
+  }
+
+  if (screen === 'raids' || screen === 'roguelike' || screen === 'pvp') {
+    const modeName = screen === 'raids' ? 'Raids' : screen === 'roguelike' ? 'Roguelike' : 'PvP'
+    return (
+      <main className="game-shell iwt2-shell">
+        <Iwt2Header save={save} onBackToGameSelect={onBackToGameSelect} />
+        <Iwt2ModePlaceholderScreen mode={modeName} onBack={() => setScreen('menu')} />
+      </main>
+    )
+  }
+
+  if (screen === 'hunter-profile') {
+    return (
+      <main className="game-shell iwt2-shell">
+        <Iwt2Header save={save} onBackToGameSelect={onBackToGameSelect} />
+        <Iwt2HunterProfileScreen save={save} onBack={() => setScreen('menu')} />
+      </main>
+    )
+  }
+
+  if (screen === 'customize-character') {
+    return (
+      <main className="game-shell iwt2-shell">
+        <Iwt2Header save={save} onBackToGameSelect={onBackToGameSelect} />
+        <Iwt2CustomizeCharacterScreen save={save} onBack={() => setScreen('menu')} />
+      </main>
+    )
+  }
+
+  if (screen === 'cloud-save') {
+    return (
+      <main className="game-shell iwt2-shell">
+        <Iwt2Header save={save} onBackToGameSelect={onBackToGameSelect} />
+        <Iwt2CloudSaveScreen save={save} onBack={() => setScreen('menu')} />
+      </main>
+    )
+  }
+
+  if (screen === 'settings') {
+    return (
+      <main className="game-shell iwt2-shell">
+        <Iwt2Header save={save} onBackToGameSelect={onBackToGameSelect} />
+        <Iwt2SettingsScreen onBack={() => setScreen('menu')} />
+      </main>
+    )
+  }
+
+  return (
+    <main className="game-shell iwt2-shell">
+      <Iwt2Header save={save} onBackToGameSelect={onBackToGameSelect} />
+
+      {screen === 'menu' && (
+        <section className="iwt2-menu-screen" data-game-nav-active="true">
+          <div className="iwt2-menu-heading">
+            <p className="eyebrow">I Want To Heal 2</p>
+            <h1>Mode Select</h1>
+          </div>
+          <div className="iwt2-menu-grid">
+            {MENU_ITEMS.map((item, index) => (
+              <button
+                className={`iwt2-menu-card ${selectedIndex === index ? 'game-selected' : ''}`}
+                data-controller-nav="skip"
+                key={item.screen}
+                onClick={() => setScreen(item.screen)}
+                onPointerDown={() => setSelectedIndex(index)}
+                type="button"
+              >
+                <span>{item.glyph}</span>
+                <div>
+                  <strong>{item.title}</strong>
+                  <small>{item.description}</small>
+                </div>
+              </button>
+            ))}
+          </div>
+        </section>
+      )}
+    </main>
+  )
+}
+
+function Iwt2Header({
+  onBackToGameSelect,
+  save,
+}: {
+  onBackToGameSelect: () => void
+  save: Iwt2Save
+}) {
+  return (
+    <header className="topbar app-header">
+      <button className="brand-button" onClick={onBackToGameSelect} type="button">
+        <strong>Games</strong>
+      </button>
+      <div className="character-summary">
+        <strong>{save.character.name}</strong>
+        <small>IWT2 Level {save.character.level}</small>
+        <small>{save.character.experience} XP</small>
+      </div>
+    </header>
+  )
+}

src/modes/iwt2/Iwt2BottomDisplay.tsx

@@ -0,0 +1,78 @@
+import { ControllerBindingLabel } from '../../components/ControllerIcons'
+import { DEFAULT_BINDINGS, useInput } from '../../input'
+import { IWT2_CLASS_METADATA, IWT2_PARTY_ORDER } from './content/classes'
+import { IWT2_ABILITY_ACTIONS, IWT2_TARGET_ACTIONS } from './content/controls'
+import { abilitiesForHealer } from './content/healerAbilities'
+
+export function Iwt2BottomDisplay() {
+  const {
+    bindings,
+    directPartyTargeting,
+    lastDevice,
+  } = useInput()
+  const activeBindings = lastDevice === 'controller'
+    ? bindings.controller
+    : DEFAULT_BINDINGS.controller
+  const abilities = abilitiesForHealer('field_medic')
+  const partyTargets = IWT2_PARTY_ORDER.map((classId) => IWT2_CLASS_METADATA[classId])
+
+  return (
+    <main className="dual-bottom-display iwt2-bottom-display">
+      <section className="dual-controls-resource iwt2-bottom-resource">
+        <div>
+          <p className="eyebrow">I Want To Heal 2</p>
+          <strong>Field Medic</strong>
+        </div>
+        <div className="dual-controls-mana">
+          <span>Mana 100 / 100</span>
+          <div className="bar mana-bar"><span style={{ width: '100%' }} /></div>
+        </div>
+      </section>
+      <section className={`dual-controls-targets ${directPartyTargeting ? 'direct' : ''}`} aria-label="Party targets">
+        {directPartyTargeting ? (
+          partyTargets.map((target, index) => {
+            const action = IWT2_TARGET_ACTIONS[index] ?? 'targetParty1'
+            const label = target.id === 'healer' ? 'Player' : target.name.replace(' Tank', '')
+            return (
+              <button type="button" key={target.id}>
+                <ControllerBindingLabel
+                  binding={activeBindings[action]}
+                  iconStyle="playstation"
+                />{' '}
+                {label}
+              </button>
+            )
+          })
+        ) : (
+          <>
+            <button type="button">
+              <ControllerBindingLabel binding="Button12" iconStyle="playstation" /> Previous Target
+            </button>
+            <button type="button">
+              Next Target <ControllerBindingLabel binding="Button13" iconStyle="playstation" />
+            </button>
+          </>
+        )}
+      </section>
+      <section className="dual-controls-spells iwt2-bottom-spell-grid" aria-label="Spells and cooldowns">
+        {abilities.map((ability, index) => {
+          const action = IWT2_ABILITY_ACTIONS[index] ?? 'ability1'
+          return (
+            <button className="spell iwt2-bottom-spell" key={ability.id} type="button">
+              <kbd>
+                <ControllerBindingLabel
+                  binding={activeBindings[action]}
+                  compact
+                  iconStyle="playstation"
+                />
+              </kbd>
+              <span className={`spell-icon spell-${ability.kind}`}>{ability.icon}</span>
+              <strong>{ability.name}</strong>
+              <small>{ability.manaCost} Mana</small>
+            </button>
+          )
+        })}
+      </section>
+    </main>
+  )
+}

src/modes/iwt2/components/AbilityBar.tsx

@@ -0,0 +1,37 @@
+import type { Iwt2HealerAbility } from '../content/healerAbilities'
+
+export function AbilityBar({
+  abilities,
+  cooldowns,
+  mana,
+  onCast,
+}: {
+  abilities: Iwt2HealerAbility[]
+  cooldowns: Record<string, number>
+  mana: number
+  onCast: (ability: Iwt2HealerAbility) => void
+}) {
+  return (
+    <div className="iwt2-ability-bar">
+      {abilities.map((ability) => {
+        const remaining = cooldowns[ability.id] ?? 0
+        const disabled = remaining > 0 || mana < ability.manaCost
+        return (
+          <button
+            aria-label={`${ability.slot}. ${ability.name}`}
+            className="iwt2-ability-button"
+            disabled={disabled}
+            key={ability.id}
+            onClick={() => onCast(ability)}
+            title={`${ability.name} - ${ability.manaCost} MP`}
+            type="button"
+          >
+            <span>{ability.icon}</span>
+            <strong>{ability.slot}</strong>
+            <i>{remaining > 0 ? `${remaining.toFixed(1)}s` : `${ability.manaCost} MP`}</i>
+          </button>
+        )
+      })}
+    </div>
+  )
+}

src/modes/iwt2/components/ArenaBars.tsx

@@ -0,0 +1,20 @@
+export function ArenaBar({
+  className = '',
+  current,
+  max,
+  shield = 0,
+}: {
+  className?: string
+  current: number
+  max: number
+  shield?: number
+}) {
+  const percent = max > 0 ? Math.max(0, Math.min(100, (current / max) * 100)) : 0
+  const shieldPercent = max > 0 ? Math.max(0, Math.min(100, (shield / max) * 100)) : 0
+  return (
+    <div className={`iwt2-bar ${className}`}>
+      <span style={{ width: `${percent}%` }} />
+      {shieldPercent > 0 && <i style={{ width: `${shieldPercent}%` }} />}
+    </div>
+  )
+}

src/modes/iwt2/components/BossHud.tsx

@@ -0,0 +1,17 @@
+import type { Iwt2BossEntityState } from '../sim'
+import { ArenaBar } from './ArenaBars'
+import { IWT2_BOSS_METADATA } from '../content/bosses'
+
+export function BossHud({ boss }: { boss: Iwt2BossEntityState }) {
+  const metadata = IWT2_BOSS_METADATA[boss.bossId]
+  return (
+    <div className="iwt2-boss-hud">
+      <div>
+        <strong>{metadata.name}</strong>
+        <small>{Math.ceil(boss.health)} / {boss.maxHealth} HP</small>
+      </div>
+      <small className="iwt2-boss-phase">{boss.attackPhase}</small>
+      <ArenaBar className="boss" current={boss.health} max={boss.maxHealth} />
+    </div>
+  )
+}

src/modes/iwt2/components/PartyFrames.tsx

@@ -0,0 +1,71 @@
+import { ControllerBindingLabel } from '../../../components/ControllerIcons'
+import type { ControllerIconStyle } from '../../../input'
+import { IWT2_CLASS_METADATA } from '../content/classes'
+import type { Iwt2EntityId, Iwt2PartyEntityState } from '../sim'
+import { ArenaBar } from './ArenaBars'
+
+export function PartyFrames({
+  party,
+  selectedPartyId,
+  targetBindings,
+  controllerIconStyle,
+  onTarget,
+}: {
+  party: Iwt2PartyEntityState[]
+  selectedPartyId: Iwt2EntityId
+  targetBindings?: Array<string | null>
+  controllerIconStyle?: ControllerIconStyle
+  onTarget: (id: Iwt2EntityId) => void
+}) {
+  return (
+    <aside className="iwt2-party-list" data-game-nav-active="true">
+      {party.map((member) => {
+        const meta = IWT2_CLASS_METADATA[member.classId]
+        const selected = member.id === selectedPartyId
+        const targetBinding = targetBindings?.[party.indexOf(member)]
+        return (
+          <button
+            className={`iwt2-party-row ${targetBinding ? 'has-target-binding' : ''} ${selected ? 'game-selected selected' : ''}`}
+            data-controller-nav="skip"
+            key={member.id}
+            onClick={() => onTarget(member.id)}
+            type="button"
+          >
+            {targetBinding && (
+              <span className="iwt2-party-target-key">
+                <ControllerBindingLabel
+                  binding={targetBinding}
+                  iconStyle={controllerIconStyle ?? 'playstation'}
+                />
+              </span>
+            )}
+            <span style={{ background: meta.color }}>{meta.icon}</span>
+            <div>
+              <div className="iwt2-party-row-title">
+                <strong>{meta.name}</strong>
+                <small>{Math.ceil(member.health)}</small>
+              </div>
+              <ArenaBar className="hp" current={member.health} max={member.maxHealth} shield={member.shield} />
+              {member.maxMana > 0 && (
+                <ArenaBar className="mana" current={member.mana} max={member.maxMana} />
+              )}
+              <div className="iwt2-party-effects">
+                {member.hotEffects.map((effect) => (
+                  <span className="iwt2-effect-badge hot" key={effect.id}>
+                    {effect.label} {Math.ceil(effect.remainingSeconds)}s
+                  </span>
+                ))}
+                {member.shield > 0 && (
+                  <span className="iwt2-effect-badge shield">
+                    Shield {Math.ceil(member.shield)}
+                  </span>
+                )}
+              </div>
+              <small className="iwt2-party-damage">Damage {Math.round(member.damageDone)}</small>
+            </div>
+          </button>
+        )
+      })}
+    </aside>
+  )
+}

src/modes/iwt2/content/balanceOverrides.ts

@@ -0,0 +1,6 @@
+import type { Iwt2BalanceOverrides } from './bosses'
+
+// Generated by local admin panel. Commit this file with intended IWT2 balance changes.
+export const IWT2_BALANCE_OVERRIDES: Iwt2BalanceOverrides = {
+  bosses: {},
+}

src/modes/iwt2/content/bosses.ts

@@ -0,0 +1,134 @@
+import { IWT2_BALANCE_OVERRIDES } from './balanceOverrides'
+
+export type Iwt2BossId = 'bulldrome' | 'yian-kut-ku'
+
+export type Iwt2BalanceOverrides = {
+  bosses?: Partial<Record<Iwt2BossId, Partial<Pick<Iwt2BossMetadata, 'maxHealth' | 'birdHealth'>>>>
+}
+
+export type Iwt2BossMetadata = {
+  id: Iwt2BossId
+  name: string
+  icon: string
+  color: string
+  accentColor: string
+  maxHealth: number
+  radius: number
+  moveSpeed: number
+  meleeRange: number
+  meleeDamage: number
+  meleeCooldown: number
+  chargeCooldown: number
+  chargeWindup: number
+  chargeSpeed: number
+  chargeDamage: number
+  chargeStunSeconds: number
+  chargeLength: number
+  chargeOvershoot: number
+  chargeWidth: number
+  slamWindup: number
+  slamRadius: number
+  slamDamage: number
+  slamStunSeconds: number
+  fireballCooldown?: number
+  fireballWindup?: number
+  fireballSpeed?: number
+  fireballDamage?: number
+  fireballRadius?: number
+  firePuddleRadius?: number
+  firePuddleDamage?: number
+  firePuddleSeconds?: number
+  birdWaveThresholds?: number[]
+  birdFlightCooldown?: number
+  birdFlightWindup?: number
+  birdFlightSpeed?: number
+  birdHealth?: number
+  birdRadius?: number
+  birdContactDamage?: number
+  birdStunSeconds?: number
+}
+
+const DEFAULT_BULLDROME_BOSS_METADATA: Iwt2BossMetadata = {
+  id: 'bulldrome',
+  name: 'Bulldrome',
+  icon: 'B',
+  color: '#8f5a3c',
+  accentColor: '#e6b17f',
+  maxHealth: 950,
+  radius: 31,
+  moveSpeed: 128,
+  meleeRange: 58,
+  meleeDamage: 9,
+  meleeCooldown: 1.05,
+  chargeCooldown: 4.75,
+  chargeWindup: 0.55,
+  chargeSpeed: 510,
+  chargeDamage: 32,
+  chargeStunSeconds: 0.75,
+  chargeLength: 560,
+  chargeOvershoot: 120,
+  chargeWidth: 62,
+  slamWindup: 0.45,
+  slamRadius: 104,
+  slamDamage: 24,
+  slamStunSeconds: 0.75,
+}
+
+const DEFAULT_YIAN_KUT_KU_BOSS_METADATA: Iwt2BossMetadata = {
+  id: 'yian-kut-ku',
+  name: 'Yian Kut Ku',
+  icon: 'Y',
+  color: '#d66a35',
+  accentColor: '#ffd166',
+  maxHealth: 400,
+  radius: 29,
+  moveSpeed: 118,
+  meleeRange: 56,
+  meleeDamage: 8,
+  meleeCooldown: 1,
+  chargeCooldown: 0,
+  chargeWindup: 0,
+  chargeSpeed: 0,
+  chargeDamage: 0,
+  chargeStunSeconds: 0,
+  chargeLength: 0,
+  chargeOvershoot: 0,
+  chargeWidth: 0,
+  slamWindup: 0,
+  slamRadius: 0,
+  slamDamage: 0,
+  slamStunSeconds: 0,
+  fireballCooldown: 3.6,
+  fireballWindup: 0.55,
+  fireballSpeed: 285,
+  fireballDamage: 12,
+  fireballRadius: 9,
+  firePuddleRadius: 42,
+  firePuddleDamage: 7,
+  firePuddleSeconds: 8,
+  birdWaveThresholds: [0.9, 0.4],
+  birdFlightCooldown: 10,
+  birdFlightWindup: 0.85,
+  birdFlightSpeed: 360,
+  birdHealth: 58,
+  birdRadius: 16,
+  birdContactDamage: 10,
+  birdStunSeconds: 0.75,
+}
+
+function applyBossOverrides(metadata: Iwt2BossMetadata): Iwt2BossMetadata {
+  const override = IWT2_BALANCE_OVERRIDES.bosses?.[metadata.id]
+  if (!override) return metadata
+  return {
+    ...metadata,
+    ...override,
+  }
+}
+
+export const BULLDROME_BOSS_METADATA: Iwt2BossMetadata = applyBossOverrides(DEFAULT_BULLDROME_BOSS_METADATA)
+export const YIAN_KUT_KU_BOSS_METADATA: Iwt2BossMetadata = applyBossOverrides(DEFAULT_YIAN_KUT_KU_BOSS_METADATA)
+
+export const IWT2_BOSS_METADATA: Record<Iwt2BossId, Iwt2BossMetadata> = {
+  bulldrome: BULLDROME_BOSS_METADATA,
+  'yian-kut-ku': YIAN_KUT_KU_BOSS_METADATA,
+}

src/modes/iwt2/content/classes.ts

@@ -0,0 +1,121 @@
+export type Iwt2PlayerClassId = 'healer' | 'paladin' | 'ranger' | 'mage' | 'rogue' | 'warrior'
+
+export type Iwt2PlayerClassRole = 'healer' | 'tank' | 'damage'
+
+export type Iwt2ClassMetadata = {
+  id: Iwt2PlayerClassId
+  name: string
+  role: Iwt2PlayerClassRole
+  icon: string
+  color: string
+  accentColor: string
+  maxHealth: number
+  moveSpeed: number
+  radius: number
+  attackRange: number
+  attackDamage: number
+  attackCooldown: number
+  castTime: number
+  projectileSpeed: number
+}
+
+export const IWT2_CLASS_METADATA: Record<Iwt2PlayerClassId, Iwt2ClassMetadata> = {
+  healer: {
+    id: 'healer',
+    name: 'Player Healer',
+    role: 'healer',
+    icon: '+',
+    color: '#2fbf71',
+    accentColor: '#b7f7cf',
+    maxHealth: 125,
+    moveSpeed: 210,
+    radius: 15,
+    attackRange: 0,
+    attackDamage: 0,
+    attackCooldown: 1,
+    castTime: 0,
+    projectileSpeed: 0,
+  },
+  paladin: {
+    id: 'paladin',
+    name: 'Paladin Tank',
+    role: 'tank',
+    icon: '🛡',
+    color: '#f2c94c',
+    accentColor: '#fff0a8',
+    maxHealth: 190,
+    moveSpeed: 165,
+    radius: 17,
+    attackRange: 44,
+    attackDamage: 7,
+    attackCooldown: 0.85,
+    castTime: 0,
+    projectileSpeed: 0,
+  },
+  ranger: {
+    id: 'ranger',
+    name: 'Ranger',
+    role: 'damage',
+    icon: '🏹',
+    color: '#4aa3df',
+    accentColor: '#b9e3ff',
+    maxHealth: 115,
+    moveSpeed: 185,
+    radius: 14,
+    attackRange: 245,
+    attackDamage: 8,
+    attackCooldown: 0.62,
+    castTime: 0.32,
+    projectileSpeed: 410,
+  },
+  mage: {
+    id: 'mage',
+    name: 'Mage',
+    role: 'damage',
+    icon: '⚚',
+    color: '#c56cf0',
+    accentColor: '#efc4ff',
+    maxHealth: 100,
+    moveSpeed: 175,
+    radius: 14,
+    attackRange: 220,
+    attackDamage: 11,
+    attackCooldown: 0.78,
+    castTime: 0.42,
+    projectileSpeed: 330,
+  },
+  rogue: {
+    id: 'rogue',
+    name: 'Rogue',
+    role: 'damage',
+    icon: '††',
+    color: '#55efc4',
+    accentColor: '#c8fff2',
+    maxHealth: 110,
+    moveSpeed: 230,
+    radius: 14,
+    attackRange: 38,
+    attackDamage: 6,
+    attackCooldown: 0.38,
+    castTime: 0,
+    projectileSpeed: 0,
+  },
+  warrior: {
+    id: 'warrior',
+    name: 'Warrior',
+    role: 'damage',
+    icon: '⚔',
+    color: '#ff7675',
+    accentColor: '#ffd0d0',
+    maxHealth: 150,
+    moveSpeed: 180,
+    radius: 16,
+    attackRange: 42,
+    attackDamage: 9,
+    attackCooldown: 0.52,
+    castTime: 0,
+    projectileSpeed: 0,
+  },
+}
+
+export const IWT2_PARTY_ORDER: Iwt2PlayerClassId[] = ['healer', 'paladin', 'ranger', 'mage', 'rogue', 'warrior']

src/modes/iwt2/content/controls.ts

@@ -0,0 +1,19 @@
+import type { InputAction } from '../../../input'
+
+export const IWT2_ABILITY_ACTIONS: InputAction[] = [
+  'ability1',
+  'ability2',
+  'ability3',
+  'ability4',
+  'ability5',
+  'ability6',
+]
+
+export const IWT2_TARGET_ACTIONS: InputAction[] = [
+  'targetParty1',
+  'targetParty2',
+  'targetParty3',
+  'targetParty4',
+  'targetParty5',
+  'targetParty6',
+]

src/modes/iwt2/content/healerAbilities.ts

@@ -0,0 +1,125 @@
+import type { Spell } from '../../../game'
+import type { Ability } from '../../../profile'
+import { toCombatSpell } from '../../../combat/rules'
+
+export type Iwt2AbilityTarget = 'party-member' | 'self' | 'ground'
+
+export type Iwt2HealerAbility = {
+  id: string
+  healerId: string
+  slot: number
+  name: string
+  icon: string
+  kind: Spell['kind']
+  power: number
+  effectType?: string
+  manaCost: number
+  cooldownSeconds: number
+  target: Iwt2AbilityTarget
+}
+
+const IWT1_DAWNWEAVER_ABILITIES: Ability[] = [
+  {
+    id: 1,
+    classId: 1,
+    slug: 'mend',
+    name: 'Mend',
+    spellType: 'direct_heal',
+    cost: 5,
+    cooldown: 0.5,
+    power: 30,
+    unlockLevel: 1,
+    glyph: '+',
+    description: 'A fast, efficient single-target heal.',
+  },
+  {
+    id: 2,
+    classId: 1,
+    slug: 'renew',
+    name: 'Renew',
+    spellType: 'heal_over_time',
+    cost: 7,
+    cooldown: 0.5,
+    power: 12,
+    unlockLevel: 1,
+    glyph: '~',
+    description: 'Heals now and continues healing over time.',
+  },
+  {
+    id: 3,
+    classId: 1,
+    slug: 'radiance',
+    name: 'Radiance',
+    spellType: 'party_heal',
+    cost: 12,
+    cooldown: 8,
+    power: 18,
+    unlockLevel: 1,
+    glyph: '*',
+    description: 'Restores health to up to 4 injured party members.',
+  },
+  {
+    id: 4,
+    classId: 1,
+    slug: 'sun-ward',
+    name: 'Sun Ward',
+    spellType: 'absorb',
+    cost: 8,
+    cooldown: 7,
+    power: 36,
+    unlockLevel: 1,
+    glyph: 'O',
+    description: 'Places a damage-absorbing shield on your target.',
+  },
+  {
+    id: 5,
+    classId: 1,
+    slug: 'purify',
+    name: 'Purify',
+    spellType: 'cleanse',
+    cost: 5,
+    cooldown: 5,
+    power: 10,
+    unlockLevel: 1,
+    glyph: 'x',
+    description: 'Removes a harmful effect and restores health.',
+  },
+  {
+    id: 6,
+    classId: 1,
+    slug: 'dawn-burst',
+    name: 'Dawn Burst',
+    spellType: 'party_heal',
+    cost: 16,
+    cooldown: 12,
+    power: 28,
+    unlockLevel: 5,
+    glyph: 'D',
+    description: 'A brilliant wave of healing for up to 4 injured allies.',
+  },
+]
+
+function toIwt2Ability(ability: Ability, index: number): Iwt2HealerAbility {
+  const spell = toCombatSpell(ability, String(index + 1))
+  return {
+    id: spell.id,
+    healerId: 'field_medic',
+    slot: index + 1,
+    name: spell.name,
+    icon: spell.glyph,
+    kind: spell.kind,
+    power: spell.power,
+    effectType: spell.effectType,
+    manaCost: spell.cost,
+    cooldownSeconds: spell.cooldown,
+    target: 'party-member',
+  }
+}
+
+export const IWT2_HEALER_ABILITIES: Record<string, Iwt2HealerAbility[]> = {
+  field_medic: IWT1_DAWNWEAVER_ABILITIES.map(toIwt2Ability),
+}
+
+export function abilitiesForHealer(healerId: string) {
+  return IWT2_HEALER_ABILITIES[healerId] ?? IWT2_HEALER_ABILITIES.field_medic
+}

src/modes/iwt2/content/index.ts

@@ -0,0 +1,18 @@
+export {
+  IWT2_CLASS_METADATA,
+  IWT2_PARTY_ORDER,
+} from './classes'
+export type {
+  Iwt2ClassMetadata,
+  Iwt2PlayerClassId,
+  Iwt2PlayerClassRole,
+} from './classes'
+
+export {
+  BULLDROME_BOSS_METADATA,
+  IWT2_BOSS_METADATA,
+} from './bosses'
+export type {
+  Iwt2BossId,
+  Iwt2BossMetadata,
+} from './bosses'

src/modes/iwt2/render/PhaserArena.tsx

@@ -0,0 +1,46 @@
+import { useEffect, useRef, type MutableRefObject } from 'react'
+import Phaser from 'phaser'
+import type { MovementVector } from '../../../input'
+import { BulldromeArenaScene } from './scenes/BulldromeArenaScene'
+import type { Iwt2ArenaState } from '../sim/arenaState'
+
+type PhaserArenaProps = {
+  movementRef: MutableRefObject<MovementVector>
+  selectedPartyIdRef: MutableRefObject<string>
+  stateRef: MutableRefObject<Iwt2ArenaState>
+  onStep: (movement: MovementVector, dtSeconds: number) => Iwt2ArenaState
+}
+
+export function PhaserArena({ movementRef, onStep, selectedPartyIdRef, stateRef }: PhaserArenaProps) {
+  const hostRef = useRef<HTMLDivElement | null>(null)
+
+  useEffect(() => {
+    if (!hostRef.current) return undefined
+    const initialState = stateRef.current
+    const scene = new BulldromeArenaScene({
+      getMovement: () => movementRef.current,
+      getSelectedPartyId: () => selectedPartyIdRef.current,
+      getState: () => stateRef.current,
+      step: onStep,
+    })
+    const game = new Phaser.Game({
+      type: Phaser.AUTO,
+      parent: hostRef.current,
+      width: initialState.bounds.width,
+      height: initialState.bounds.height,
+      backgroundColor: '#10141b',
+      pixelArt: false,
+      scale: {
+        mode: Phaser.Scale.FIT,
+        autoCenter: Phaser.Scale.CENTER_BOTH,
+      },
+      scene,
+    })
+
+    return () => {
+      game.destroy(true)
+    }
+  }, [movementRef, onStep, selectedPartyIdRef, stateRef])
+
+  return <div className="iwt2-phaser-host" ref={hostRef} />
+}

src/modes/iwt2/render/scenes/BulldromeArenaScene.ts

@@ -0,0 +1,281 @@
+import Phaser from 'phaser'
+import type { MovementVector } from '../../../../input'
+import { IWT2_BOSS_METADATA } from '../../content/bosses'
+import { IWT2_CLASS_METADATA } from '../../content/classes'
+import type {
+  Iwt2ArenaIndicator,
+  Iwt2ArenaState,
+  Iwt2BossEntityState,
+  Iwt2GroundHazardState,
+  Iwt2HostileAddState,
+  Iwt2PartyEntityState,
+  Iwt2Vec2,
+} from '../../sim'
+
+type SceneDeps = {
+  getMovement: () => MovementVector
+  getSelectedPartyId: () => string
+  getState: () => Iwt2ArenaState
+  step: (movement: MovementVector, dtSeconds: number) => Iwt2ArenaState
+}
+
+type DrawableEntity = Iwt2PartyEntityState | Iwt2BossEntityState | Iwt2HostileAddState
+
+export class BulldromeArenaScene extends Phaser.Scene {
+  private deps: SceneDeps
+  private arenaGraphics?: Phaser.GameObjects.Graphics
+  private entityGraphics?: Phaser.GameObjects.Graphics
+  private telegraphGraphics?: Phaser.GameObjects.Graphics
+  private labels = new Map<string, Phaser.GameObjects.Text>()
+  private lastHudPublish = 0
+
+  constructor(deps: SceneDeps) {
+    super('bulldrome-arena')
+    this.deps = deps
+  }
+
+  create() {
+    this.cameras.main.setBackgroundColor('#10141b')
+    this.arenaGraphics = this.add.graphics()
+    this.telegraphGraphics = this.add.graphics()
+    this.entityGraphics = this.add.graphics()
+    this.drawState(this.deps.getState())
+  }
+
+  update(_: number, delta: number) {
+    const state = this.deps.step(this.deps.getMovement(), Math.min(0.05, delta / 1000))
+    this.drawState(state)
+  }
+
+  private drawState(state: Iwt2ArenaState) {
+    if (!this.arenaGraphics || !this.entityGraphics || !this.telegraphGraphics) return
+    this.drawArena(state)
+    this.drawTelegraphs(state)
+    this.drawEntities(state)
+    this.drawProjectiles(state)
+    this.lastHudPublish += 1
+  }
+
+  private drawArena(state: Iwt2ArenaState) {
+    const graphics = this.arenaGraphics!
+    graphics.clear()
+    graphics.lineStyle(3, 0x3c4a59, 1)
+    graphics.fillStyle(0x171d24, 1)
+    graphics.fillRoundedRect(0, 0, state.bounds.width, state.bounds.height, 12)
+    graphics.strokeRoundedRect(0, 0, state.bounds.width, state.bounds.height, 12)
+
+    graphics.lineStyle(1, 0x26313d, 0.55)
+    for (let x = 80; x < state.bounds.width; x += 80) {
+      graphics.lineBetween(x, 0, x, state.bounds.height)
+    }
+    for (let y = 80; y < state.bounds.height; y += 80) {
+      graphics.lineBetween(0, y, state.bounds.width, y)
+    }
+  }
+
+  private drawTelegraphs(state: Iwt2ArenaState) {
+    const graphics = this.telegraphGraphics!
+    graphics.clear()
+    state.indicators.forEach((indicator) => drawIndicator(graphics, indicator))
+  }
+
+  private drawEntities(state: Iwt2ArenaState) {
+    const graphics = this.entityGraphics!
+    graphics.clear()
+    for (const hazard of state.hazards) drawHazard(graphics, hazard)
+    const entities: DrawableEntity[] = [...state.party, ...state.hostileAdds, state.boss]
+    const liveIds = new Set<string>(entities.map((entity) => entity.id))
+
+    for (const entity of entities.sort(entitySort)) {
+      const stunned = entity.kind === 'party' && (entity.status.stunnedSeconds > 0 || entity.status.knockedDownSeconds > 0)
+      const alpha = entity.health <= 0 ? 0.35 : stunned ? 0.55 : 1
+      const color = entityColor(entity)
+      graphics.fillStyle(Number.parseInt(color.slice(1), 16), alpha)
+      graphics.lineStyle(entity.kind === 'party' && entity.aiRole === 'player' ? 4 : 2, entity.kind === 'boss' ? 0xfff0b8 : 0x0a0c10, 1)
+      if (entity.kind === 'boss') {
+        graphics.fillEllipse(entity.position.x, entity.position.y, entity.radius * 2.4, entity.radius * 1.75)
+        graphics.strokeEllipse(entity.position.x, entity.position.y, entity.radius * 2.4, entity.radius * 1.75)
+      } else if (entity.kind === 'hostileAdd') {
+        const wing = entity.radius * 1.55
+        graphics.fillTriangle(
+          entity.position.x + entity.facing.x * wing,
+          entity.position.y,
+          entity.position.x - entity.facing.x * entity.radius,
+          entity.position.y - entity.radius,
+          entity.position.x - entity.facing.x * entity.radius,
+          entity.position.y + entity.radius,
+        )
+        graphics.strokeTriangle(
+          entity.position.x + entity.facing.x * wing,
+          entity.position.y,
+          entity.position.x - entity.facing.x * entity.radius,
+          entity.position.y - entity.radius,
+          entity.position.x - entity.facing.x * entity.radius,
+          entity.position.y + entity.radius,
+        )
+      } else {
+        if (entity.id === this.deps.getSelectedPartyId()) {
+          graphics.lineStyle(4, 0xfff4a8, 0.95)
+          graphics.strokeCircle(entity.position.x, entity.position.y, entity.radius + 8)
+        }
+        graphics.fillCircle(entity.position.x, entity.position.y, entity.radius)
+        graphics.strokeCircle(entity.position.x, entity.position.y, entity.radius)
+      }
+      this.drawLabel(entity)
+      this.drawHealthBar(graphics, entity)
+    }
+
+    for (const [id, label] of this.labels) {
+      if (!liveIds.has(id)) {
+        label.destroy()
+        this.labels.delete(id)
+      }
+    }
+  }
+
+  private drawProjectiles(state: Iwt2ArenaState) {
+    const graphics = this.entityGraphics!
+    for (const projectile of state.projectiles) {
+      const color = Number.parseInt(projectile.color.slice(1), 16)
+      graphics.fillStyle(color, 0.95)
+      graphics.lineStyle(projectile.projectileKind === 'magic' || projectile.projectileKind === 'fireball' ? 3 : 2, color, 0.75)
+      graphics.strokeCircle(projectile.position.x, projectile.position.y, projectile.radius + 3)
+      graphics.fillCircle(projectile.position.x, projectile.position.y, projectile.radius)
+    }
+  }
+
+  private drawLabel(entity: DrawableEntity) {
+    let label = this.labels.get(entity.id)
+    const icon = entityIcon(entity)
+    if (!label) {
+      label = this.add.text(entity.position.x, entity.position.y, icon, {
+        align: 'center',
+        color: '#fff7df',
+        fontFamily: 'ui-monospace, Consolas, monospace',
+        fontSize: entity.kind === 'boss' ? '20px' : entity.kind === 'hostileAdd' ? '13px' : '15px',
+        fontStyle: '900',
+      }).setOrigin(0.5)
+      this.labels.set(entity.id, label)
+    }
+    const stunned = entity.kind === 'party' && (entity.status.stunnedSeconds > 0 || entity.status.knockedDownSeconds > 0)
+    label.setText(stunned ? '!' : icon)
+    label.setPosition(entity.position.x, entity.position.y - (entity.kind === 'boss' ? 1 : 0))
+    label.setAlpha(entity.health <= 0 ? 0.35 : 1)
+  }
+
+  private drawHealthBar(graphics: Phaser.GameObjects.Graphics, entity: DrawableEntity) {
+    const width = entity.kind === 'boss' ? 92 : 34
+    const height = entity.kind === 'boss' ? 8 : 7
+    const y = entity.position.y + entity.radius + 8
+    const ratio = Math.max(0, Math.min(1, entity.health / entity.maxHealth))
+    graphics.fillStyle(0x050608, 0.9)
+    graphics.fillRect(entity.position.x - width / 2, y, width, height)
+    graphics.fillStyle(ratio > 0.5 ? 0x4ac77d : ratio > 0.25 ? 0xf1c663 : 0xf05b4f, 1)
+    graphics.fillRect(entity.position.x - width / 2, y, width * ratio, height)
+    if (entity.kind === 'party' && entity.shield > 0) {
+      const shieldRatio = Math.max(0, Math.min(1, entity.shield / entity.maxHealth))
+      graphics.fillStyle(0x58a8ff, 0.92)
+      graphics.fillRect(entity.position.x + width / 2 - width * shieldRatio, y, width * shieldRatio, height)
+    }
+  }
+}
+
+function entitySort(a: DrawableEntity, b: DrawableEntity): number {
+  const rank = { boss: 0, hostileAdd: 1, party: 2 } satisfies Record<DrawableEntity['kind'], number>
+  return rank[a.kind] - rank[b.kind]
+}
+
+function entityColor(entity: DrawableEntity): string {
+  if (entity.kind === 'boss') return IWT2_BOSS_METADATA[entity.bossId].color
+  if (entity.kind === 'hostileAdd') return '#f0b84f'
+  return IWT2_CLASS_METADATA[entity.classId].color
+}
+
+function entityIcon(entity: DrawableEntity): string {
+  if (entity.kind === 'boss') return IWT2_BOSS_METADATA[entity.bossId].icon
+  if (entity.kind === 'hostileAdd') return 'v'
+  return IWT2_CLASS_METADATA[entity.classId].icon
+}
+
+function drawHazard(graphics: Phaser.GameObjects.Graphics, hazard: Iwt2GroundHazardState) {
+  const ratio = Math.max(0, Math.min(1, hazard.remainingSeconds / Math.max(0.001, hazard.fadeSeconds)))
+  const alpha = hazard.remainingSeconds <= hazard.fadeSeconds ? 0.16 + ratio * 0.2 : 0.34
+  graphics.fillStyle(0xff7a2f, alpha)
+  graphics.lineStyle(2, 0xffc15a, 0.55)
+  graphics.fillCircle(hazard.position.x, hazard.position.y, hazard.radius)
+  graphics.strokeCircle(hazard.position.x, hazard.position.y, hazard.radius)
+}
+
+function drawIndicator(graphics: Phaser.GameObjects.Graphics, indicator: Iwt2ArenaIndicator) {
+  const color = Number.parseInt(indicator.color.slice(1), 16)
+  const active = indicator.phase === 'active'
+  graphics.lineStyle(active ? 8 : 5, color, indicator.lineAlpha ?? (active ? 0.76 : 0.5))
+  graphics.fillStyle(color, indicator.fillAlpha ?? (active ? 0.16 : 0.09))
+
+  if (indicator.kind === 'lane') {
+    const points = laneDangerPolygon(indicator.start, indicator.end, indicator.width)
+    graphics.fillPoints(points, true)
+    graphics.strokePoints(points, true)
+    return
+  }
+
+  if (indicator.kind === 'circle') {
+    graphics.strokeCircle(indicator.position.x, indicator.position.y, indicator.radius)
+    graphics.fillCircle(indicator.position.x, indicator.position.y, indicator.radius)
+    return
+  }
+
+  if (indicator.kind === 'cone') {
+    const points = coneDangerPolygon(
+      indicator.origin,
+      indicator.direction,
+      indicator.range,
+      indicator.angleRadians,
+    )
+    graphics.fillPoints(points, true)
+    graphics.strokePoints(points, true)
+    return
+  }
+
+  graphics.strokeCircle(indicator.position.x, indicator.position.y, indicator.outerRadius)
+  graphics.fillCircle(indicator.position.x, indicator.position.y, indicator.outerRadius)
+  graphics.lineStyle(active ? 5 : 3, color, indicator.lineAlpha ?? 0.6)
+  graphics.strokeCircle(indicator.position.x, indicator.position.y, indicator.innerRadius)
+}
+
+function laneDangerPolygon(start: Iwt2Vec2, end: Iwt2Vec2, halfWidth: number) {
+  const dx = end.x - start.x
+  const dy = end.y - start.y
+  const length = Math.max(1, Math.hypot(dx, dy))
+  const normal = {
+    x: (-dy / length) * halfWidth,
+    y: (dx / length) * halfWidth,
+  }
+  return [
+    new Phaser.Math.Vector2(start.x + normal.x, start.y + normal.y),
+    new Phaser.Math.Vector2(end.x + normal.x, end.y + normal.y),
+    new Phaser.Math.Vector2(end.x - normal.x, end.y - normal.y),
+    new Phaser.Math.Vector2(start.x - normal.x, start.y - normal.y),
+  ]
+}
+
+function coneDangerPolygon(
+  origin: Iwt2Vec2,
+  direction: Iwt2Vec2,
+  range: number,
+  angleRadians: number,
+) {
+  const baseAngle = Math.atan2(direction.y, direction.x)
+  const halfAngle = angleRadians / 2
+  const points = [new Phaser.Math.Vector2(origin.x, origin.y)]
+  const segmentCount = 14
+  for (let index = 0; index <= segmentCount; index += 1) {
+    const t = index / segmentCount
+    const angle = baseAngle - halfAngle + angleRadians * t
+    points.push(new Phaser.Math.Vector2(
+      origin.x + Math.cos(angle) * range,
+      origin.y + Math.sin(angle) * range,
+    ))
+  }
+  return points
+}

src/modes/iwt2/save/iwt2Repository.ts

@@ -0,0 +1,115 @@
+export type Iwt2InventoryItem = {
+  id: string
+  name: string
+  quantity: number
+  rarity: 'common' | 'uncommon' | 'rare' | 'epic' | 'legendary'
+}
+
+export type Iwt2CollectionLog = {
+  bossKills: Record<string, number>
+  dropsFound: Record<string, number>
+}
+
+export type Iwt2Save = {
+  version: 1
+  updatedAt: number
+  character: {
+    name: string
+    level: number
+    experience: number
+  }
+  inventory: Iwt2InventoryItem[]
+  collectionLog: Iwt2CollectionLog
+}
+
+const IWT2_SAVE_KEY = 'i-want-to-heal-2:save:v1'
+
+export function createDefaultIwt2Save(): Iwt2Save {
+  return {
+    version: 1,
+    updatedAt: Date.now(),
+    character: {
+      name: 'Healer',
+      level: 1,
+      experience: 0,
+    },
+    inventory: [],
+    collectionLog: {
+      bossKills: {},
+      dropsFound: {},
+    },
+  }
+}
+
+function normalizeSave(value: unknown): Iwt2Save {
+  if (!value || typeof value !== 'object') return createDefaultIwt2Save()
+  const candidate = value as Partial<Iwt2Save>
+  if (candidate.version !== 1) return createDefaultIwt2Save()
+  return {
+    version: 1,
+    updatedAt: typeof candidate.updatedAt === 'number' ? candidate.updatedAt : Date.now(),
+    character: {
+      name: candidate.character?.name || 'Healer',
+      level: Math.max(1, Math.floor(candidate.character?.level ?? 1)),
+      experience: Math.max(0, Math.floor(candidate.character?.experience ?? 0)),
+    },
+    inventory: Array.isArray(candidate.inventory) ? candidate.inventory : [],
+    collectionLog: {
+      bossKills: candidate.collectionLog?.bossKills ?? {},
+      dropsFound: candidate.collectionLog?.dropsFound ?? {},
+    },
+  }
+}
+
+export function loadIwt2Save(): Iwt2Save {
+  try {
+    return normalizeSave(JSON.parse(window.localStorage.getItem(IWT2_SAVE_KEY) ?? 'null'))
+  } catch {
+    return createDefaultIwt2Save()
+  }
+}
+
+export function writeIwt2Save(save: Iwt2Save) {
+  window.localStorage.setItem(IWT2_SAVE_KEY, JSON.stringify({
+    ...save,
+    updatedAt: Date.now(),
+  }))
+}
+
+export function recordIwt2BossKill(save: Iwt2Save, bossId: string): Iwt2Save {
+  const drop = bossDropFor(bossId)
+  return {
+    ...save,
+    updatedAt: Date.now(),
+    character: {
+      ...save.character,
+      experience: save.character.experience + 125,
+      level: Math.max(save.character.level, 1 + Math.floor((save.character.experience + 125) / 500)),
+    },
+    inventory: [
+      ...save.inventory,
+      {
+        id: `${drop.id}-${Date.now()}`,
+        name: drop.name,
+        quantity: 1,
+        rarity: 'common',
+      },
+    ],
+    collectionLog: {
+      ...save.collectionLog,
+      bossKills: {
+        ...save.collectionLog.bossKills,
+        [bossId]: (save.collectionLog.bossKills[bossId] ?? 0) + 1,
+      },
+      dropsFound: {
+        ...save.collectionLog.dropsFound,
+        [drop.id]: (save.collectionLog.dropsFound[drop.id] ?? 0) + 1,
+      },
+    },
+  }
+}
+
+function bossDropFor(bossId: string): { id: string, name: string } {
+  if (bossId === 'yian-kut-ku') return { id: 'yian-kut-ku-scale', name: 'Yian Kut Ku Scale' }
+  return { id: 'raw-bulldrome-coin', name: 'Raw Bulldrome Coin' }
+}

src/modes/iwt2/screens/BossArenaScreen.tsx

@@ -0,0 +1,354 @@
+import { useCallback, useEffect, useMemo, useRef, useState, type CSSProperties } from 'react'
+import type { MovementVector } from '../../../input'
+import { useGameAction, useInput, useMovementVectorRef } from '../../../input'
+import {
+  createInitialIwt2ArenaState,
+  tickIwt2Arena,
+  type Iwt2ArenaState,
+} from '../sim/arenaState'
+import type { Iwt2EntityId } from '../sim'
+import { castIwt2HealerAbility } from '../sim'
+import { PhaserArena } from '../render/PhaserArena'
+import {
+  recordIwt2BossKill,
+  type Iwt2Save,
+} from '../save/iwt2Repository'
+import { AbilityBar } from '../components/AbilityBar'
+import { BossHud } from '../components/BossHud'
+import { PartyFrames } from '../components/PartyFrames'
+import { IWT2_ABILITY_ACTIONS, IWT2_TARGET_ACTIONS } from '../content/controls'
+import { abilitiesForHealer, type Iwt2HealerAbility } from '../content/healerAbilities'
+import { IWT2_BOSS_METADATA, type Iwt2BossId } from '../content/bosses'
+
+type ArenaStatus = 'playing' | 'paused' | 'victory' | 'defeat'
+type OverlayAction = 'primary' | 'menu'
+
+type BossArenaScreenProps = {
+  bossId: Iwt2BossId
+  save: Iwt2Save
+  onBack: () => void
+  onSaveUpdated: (save: Iwt2Save) => void
+}
+
+export function BossArenaScreen({ bossId, save, onBack, onSaveUpdated }: BossArenaScreenProps) {
+  const bossMetadata = IWT2_BOSS_METADATA[bossId]
+  const [arenaState, setArenaState] = useState<Iwt2ArenaState>(() => createInitialIwt2ArenaState(bossId))
+  const [abilityCooldowns, setAbilityCooldowns] = useState<Record<string, number>>({})
+  const [status, setStatus] = useState<ArenaStatus>('playing')
+  const [selectedOverlayAction, setSelectedOverlayAction] = useState<OverlayAction>('primary')
+  const [selectedPartyId, setSelectedPartyId] = useState<Iwt2EntityId>('player-healer')
+  const stateRef = useRef(arenaState)
+  const statusRef = useRef(status)
+  const selectedPartyIdRef = useRef<Iwt2EntityId>(selectedPartyId)
+  const saveRef = useRef(save)
+  const killRecordedRef = useRef(false)
+  const lastPublishTimeRef = useRef(0)
+  const lastHudSignatureRef = useRef('')
+  const abilityCooldownsRef = useRef<Record<string, number>>({})
+  const movementRef = useMovementVectorRef(status === 'playing')
+  const {
+    bindings,
+    controllerIconStyle,
+    directPartyTargeting,
+    lastDevice,
+  } = useInput()
+  const activeBindings = bindings[lastDevice]
+
+  useEffect(() => {
+    stateRef.current = arenaState
+  }, [arenaState])
+
+  useEffect(() => {
+    statusRef.current = status
+  }, [status])
+
+  useEffect(() => {
+    selectedPartyIdRef.current = selectedPartyId
+  }, [selectedPartyId])
+
+  useEffect(() => {
+    saveRef.current = save
+  }, [save])
+
+  const resetArena = useCallback(() => {
+    const next = createInitialIwt2ArenaState(bossId)
+    killRecordedRef.current = false
+    abilityCooldownsRef.current = {}
+    lastHudSignatureRef.current = arenaHudSignature(next)
+    stateRef.current = next
+    setArenaState(next)
+    setAbilityCooldowns({})
+    setSelectedOverlayAction('primary')
+    setStatus('playing')
+  }, [bossId])
+
+  const showOverlay = useCallback((nextStatus: Exclude<ArenaStatus, 'playing'>) => {
+    setSelectedOverlayAction('primary')
+    setStatus(nextStatus)
+  }, [])
+
+  const abilities = useMemo(
+    () => abilitiesForHealer('field_medic'),
+    [],
+  )
+
+  const castAbility = useCallback((ability: Iwt2HealerAbility) => {
+    if (statusRef.current !== 'playing') return
+    if ((abilityCooldownsRef.current[ability.id] ?? 0) > 0) return
+    const result = castIwt2HealerAbility(stateRef.current, ability, selectedPartyIdRef.current)
+    if (!result.cast) return
+
+    const nextCooldowns = {
+      ...abilityCooldownsRef.current,
+      [ability.id]: ability.cooldownSeconds,
+    }
+    abilityCooldownsRef.current = nextCooldowns
+    stateRef.current = result.state
+    lastHudSignatureRef.current = arenaHudSignature(result.state)
+    setAbilityCooldowns(nextCooldowns)
+    setArenaState(result.state)
+  }, [])
+
+  useGameAction((action, device) => {
+    if (device === 'controller' && statusRef.current !== 'playing') {
+      if (action.startsWith('navigate')) {
+        setSelectedOverlayAction((current) => current === 'primary' ? 'menu' : 'primary')
+        return
+      }
+      if (action === 'confirm') {
+        if (selectedOverlayAction === 'menu') onBack()
+        else if (statusRef.current === 'paused') setStatus('playing')
+        else resetArena()
+        return
+      }
+      if (action === 'back') {
+        if (statusRef.current === 'paused') setStatus('playing')
+        else onBack()
+        return
+      }
+    }
+    if (statusRef.current === 'playing' && action.startsWith('ability')) {
+      const ability = abilities[IWT2_ABILITY_ACTIONS.indexOf(action)]
+      if (ability) castAbility(ability)
+      return
+    }
+    if (
+      device === 'controller'
+      && statusRef.current === 'playing'
+      && !directPartyTargeting
+      && (
+        action === 'navigateUp'
+        || action === 'navigateLeft'
+        || action === 'previousTarget'
+        || action === 'navigateDown'
+        || action === 'navigateRight'
+        || action === 'nextTarget'
+      )
+    ) {
+      const previous = action === 'navigateUp' || action === 'navigateLeft' || action === 'previousTarget'
+      setSelectedPartyId((current) => nextTargetId(stateRef.current, current, previous ? -1 : 1))
+      return
+    }
+    if (action.startsWith('targetParty')) {
+      const index = Number(action.replace('targetParty', '')) - 1
+      const target = stateRef.current.party[index]
+      if (target) setSelectedPartyId(target.id)
+      return
+    }
+    if (device !== 'controller') return
+    if (action === 'pause' || action === 'back') {
+      if (statusRef.current === 'playing') showOverlay('paused')
+      else if (statusRef.current === 'paused') setStatus('playing')
+    }
+  })
+
+  const onStep = useCallback((movement: MovementVector, dtSeconds: number) => {
+    if (statusRef.current !== 'playing') return stateRef.current
+    abilityCooldownsRef.current = tickCooldowns(abilityCooldownsRef.current, dtSeconds)
+    const next = tickIwt2Arena(stateRef.current, {
+      moveX: movement.x,
+      moveY: movement.y,
+    }, dtSeconds)
+    stateRef.current = next
+
+    if (next.boss.health <= 0 && !killRecordedRef.current) {
+      killRecordedRef.current = true
+      const updatedSave = recordIwt2BossKill(saveRef.current, bossId)
+      saveRef.current = updatedSave
+      onSaveUpdated(updatedSave)
+      showOverlay('victory')
+    } else if (next.party.every((member) => member.health <= 0)) {
+      showOverlay('defeat')
+    }
+
+    const hudSignature = arenaHudSignature(next)
+    if (
+      hudSignature !== lastHudSignatureRef.current
+      || next.time - lastPublishTimeRef.current >= 0.08
+      || next.boss.health <= 0
+    ) {
+      lastHudSignatureRef.current = hudSignature
+      lastPublishTimeRef.current = next.time
+      setArenaState(next)
+      setAbilityCooldowns(abilityCooldownsRef.current)
+    }
+    return next
+  }, [bossId, onSaveUpdated, showOverlay])
+
+  const targetBindings = directPartyTargeting
+    ? IWT2_TARGET_ACTIONS.map((action) => activeBindings[action] ?? null)
+    : undefined
+  const playerMana = arenaState.party.find((member) => member.id === 'player-healer')?.mana ?? 0
+  const alivePartyCount = arenaState.party.filter((member) => member.health > 0).length
+  const totalPartyDamage = arenaState.party.reduce((total, member) => total + member.damageDone, 0)
+  const overlayPrimaryLabel = status === 'paused' ? 'Resume' : 'Restart'
+  const overlayTitle = status === 'victory'
+    ? `${bossMetadata.name} Down`
+    : status === 'defeat'
+      ? 'Party Defeated'
+      : 'Arena Paused'
+  const overlayEyebrow = status === 'victory'
+    ? 'Hunt Complete'
+    : status === 'defeat'
+      ? 'Recovery'
+      : 'Paused'
+  const overlayTone = status === 'victory'
+    ? 'is-victory'
+    : status === 'defeat'
+      ? 'is-defeat'
+      : 'is-paused'
+
+  return (
+    <main
+      className="game-shell iwt2-arena-shell"
+      data-combat-active={status === 'playing' ? 'true' : 'false'}
+      data-continuous-movement-active={status === 'playing' ? 'true' : undefined}
+    >
+      <section className="iwt2-arena-layout">
+        <div className="iwt2-arena-stage">
+          <BossHud boss={arenaState.boss} />
+          <PartyFrames
+            controllerIconStyle={controllerIconStyle}
+            onTarget={setSelectedPartyId}
+            party={arenaState.party}
+            selectedPartyId={selectedPartyId}
+            targetBindings={targetBindings}
+          />
+
+          <PhaserArena
+            movementRef={movementRef}
+            onStep={onStep}
+            selectedPartyIdRef={selectedPartyIdRef}
+            stateRef={stateRef}
+          />
+          {status !== 'playing' && (
+            <div className={`pause-screen iwt2-arena-overlay ${overlayTone}`} data-game-nav-active="true">
+              <div className="iwt2-result-panel">
+                <div className="iwt2-result-crest" style={{ '--boss-color': bossMetadata.color, '--boss-accent': bossMetadata.accentColor } as CSSProperties}>
+                  <span>{bossMetadata.icon}</span>
+                </div>
+                <p className="eyebrow">{overlayEyebrow}</p>
+                <h1>{overlayTitle}</h1>
+                {status !== 'paused' && (
+                  <div className="iwt2-result-summary" aria-label="Arena result summary">
+                    <span>
+                      <strong>{formatArenaTime(arenaState.time)}</strong>
+                      Clear
+                    </span>
+                    <span>
+                      <strong>{alivePartyCount}/{arenaState.party.length}</strong>
+                      Standing
+                    </span>
+                    <span>
+                      <strong>{Math.round(totalPartyDamage)}</strong>
+                      Damage
+                    </span>
+                  </div>
+                )}
+                {status === 'victory' && (
+                  <div className="iwt2-result-reward">
+                    <span>+125 XP</span>
+                    <span>Common carve</span>
+                    <span>Log +1</span>
+                  </div>
+                )}
+                <div className="iwt2-overlay-actions">
+                  <button
+                    className={`iwt2-result-button is-primary ${selectedOverlayAction === 'primary' ? 'game-selected' : ''}`}
+                    data-game-selected={selectedOverlayAction === 'primary' ? 'true' : undefined}
+                    onClick={status === 'paused' ? () => setStatus('playing') : resetArena}
+                    type="button"
+                  >
+                    {overlayPrimaryLabel}
+                  </button>
+                  <button
+                    className={`iwt2-result-button is-secondary ${selectedOverlayAction === 'menu' ? 'game-selected' : ''}`}
+                    data-game-selected={selectedOverlayAction === 'menu' ? 'true' : undefined}
+                    onClick={onBack}
+                    type="button"
+                  >
+                    Menu
+                  </button>
+                </div>
+                {lastDevice === 'controller' && (
+                  <small className="iwt2-result-hint">D-pad selects, A confirms, B exits</small>
+                )}
+              </div>
+            </div>
+          )}
+
+          <AbilityBar
+            abilities={abilities}
+            cooldowns={abilityCooldowns}
+            mana={playerMana}
+            onCast={castAbility}
+          />
+        </div>
+      </section>
+    </main>
+  )
+}
+
+function formatArenaTime(seconds: number): string {
+  const safeSeconds = Math.max(0, Math.floor(seconds))
+  const minutes = Math.floor(safeSeconds / 60)
+  const remainder = safeSeconds % 60
+  return `${minutes}:${remainder.toString().padStart(2, '0')}`
+}
+
+function arenaHudSignature(state: Iwt2ArenaState): string {
+  return [
+    state.boss.id,
+    Math.ceil(state.boss.health),
+    state.boss.attackPhase,
+    state.hostileAdds.length,
+    state.hazards.length,
+    ...state.party.map((member) => [
+      member.id,
+      Math.ceil(member.health),
+      Math.ceil(member.shield),
+      Math.ceil(member.mana),
+      Math.ceil(Math.max(member.status.stunnedSeconds, member.status.knockedDownSeconds) * 10),
+      member.hotEffects.map((effect) => `${effect.id}:${Math.ceil(effect.remainingSeconds)}:${Math.ceil(effect.nextTickInSeconds * 10)}`).join(','),
+    ].join(':')),
+  ].join('|')
+}
+
+function nextTargetId(state: Iwt2ArenaState, currentId: Iwt2EntityId, direction: -1 | 1): Iwt2EntityId {
+  const living = state.party.filter((member) => member.health > 0)
+  const targets = living.length > 0 ? living : state.party
+  const currentIndex = Math.max(0, targets.findIndex((member) => member.id === currentId))
+  const nextIndex = (currentIndex + direction + targets.length) % targets.length
+  return targets[nextIndex]?.id ?? currentId
+}
+
+function tickCooldowns(cooldowns: Record<string, number>, dt: number) {
+  let changed = false
+  const next: Record<string, number> = {}
+  for (const [id, remaining] of Object.entries(cooldowns)) {
+    const value = Math.max(0, remaining - dt)
+    if (value !== remaining) changed = true
+    if (value > 0) next[id] = value
+  }
+  return changed ? next : cooldowns
+}

src/modes/iwt2/screens/Iwt2ShellScreens.tsx

@@ -0,0 +1,337 @@
+import { useMemo, useState, type ReactNode } from 'react'
+import { ControllerStylePreview } from '../../../components/ControllerIcons'
+import { useGameAction, useInput, type ControllerIconStyle } from '../../../input'
+import type { Iwt2Save } from '../save/iwt2Repository'
+import type { Iwt2BossId } from '../content/bosses'
+
+type Iwt2NavAction = {
+  key: string
+  label: string
+  detail?: string
+  value?: string
+  onConfirm: () => void
+}
+
+type Iwt2ScreenShellProps = {
+  title: string
+  eyebrow?: string
+  onBack: () => void
+  children: ReactNode
+}
+
+type Iwt2ActionListProps = {
+  actions: Iwt2NavAction[]
+}
+
+function useIwt2ActionList(actions: Iwt2NavAction[]) {
+  const [selectedIndex, setSelectedIndex] = useState(0)
+  const activeIndex = Math.min(selectedIndex, Math.max(0, actions.length - 1))
+
+  useGameAction((action, device) => {
+    if (device !== 'controller' || actions.length === 0) return
+    if (action === 'navigateUp' || action === 'navigateLeft') {
+      setSelectedIndex((current) => Math.max(0, current - 1))
+    } else if (action === 'navigateDown' || action === 'navigateRight') {
+      setSelectedIndex((current) => Math.min(actions.length - 1, current + 1))
+    } else if (action === 'confirm') {
+      actions[activeIndex]?.onConfirm()
+    }
+  })
+
+  return { selectedIndex: activeIndex, setSelectedIndex }
+}
+
+const MODE_DESCRIPTIONS = {
+  Raids: 'Large-party boss fights will use the same 2D arena contract with larger rosters and raid-scale mechanics.',
+  Roguelike: 'Runs will chain rooms, rewards, healer builds, and IWT2-only inventory progression.',
+  PvP: 'Player-vs-player healing scenarios will reuse controller targeting and class identity without IWT1 state bleed.',
+} satisfies Record<'Raids' | 'Roguelike' | 'PvP', string>
+
+const CONTROLLER_ICON_OPTIONS: ControllerIconStyle[] = ['playstation', 'xbox', 'nintendo']
+
+const CONTROLLER_ICON_LABELS: Record<ControllerIconStyle, string> = {
+  xbox: 'Xbox',
+  playstation: 'PlayStation',
+  nintendo: 'Nintendo',
+}
+
+export function Iwt2ScreenShell({
+  children,
+  eyebrow = 'I Want To Heal 2',
+  onBack,
+  title,
+}: Iwt2ScreenShellProps) {
+  useGameAction((action, device) => {
+    if (device === 'controller' && action === 'back') onBack()
+  })
+
+  return (
+    <section className="content-screen iwt2-screen-shell" data-game-nav-active="true">
+      <div className="screen-heading">
+        <div>
+          <p className="eyebrow">{eyebrow}</p>
+          <h1>{title}</h1>
+        </div>
+        <button className="back-button" data-controller-nav="skip" onClick={onBack} type="button">
+          Back
+        </button>
+      </div>
+      {children}
+    </section>
+  )
+}
+
+export function Iwt2ActionList({ actions }: Iwt2ActionListProps) {
+  const { selectedIndex, setSelectedIndex } = useIwt2ActionList(actions)
+
+  return (
+    <div className="iwt2-action-list">
+      {actions.map((action, index) => (
+        <button
+          className={`iwt2-action-row ${selectedIndex === index ? 'game-selected selected' : ''}`}
+          data-controller-nav="skip"
+          key={action.key}
+          onClick={action.onConfirm}
+          onPointerDown={() => setSelectedIndex(index)}
+          type="button"
+        >
+          <span>
+            <strong>{action.label}</strong>
+            {action.detail && <small>{action.detail}</small>}
+          </span>
+          {action.value && <em>{action.value}</em>}
+        </button>
+      ))}
+    </div>
+  )
+}
+
+export function Iwt2DungeonsScreen({
+  onBack,
+  onOpenBoss,
+}: {
+  onBack: () => void
+  onOpenBoss: (bossId: Iwt2BossId) => void
+}) {
+  const actions = useMemo<Iwt2NavAction[]>(() => [
+    {
+      key: 'bulldrome',
+      label: 'Bulldrome Arena',
+      detail: 'Level 1 field boss. Charge lanes, tank pressure, and periodic ground slam.',
+      value: 'Ready',
+      onConfirm: () => onOpenBoss('bulldrome'),
+    },
+    {
+      key: 'yian-kut-ku',
+      label: 'Yian Kut Ku Arena',
+      detail: 'Bouncing fireballs, capped fire puddles, and bird waves at 90% and 40% health.',
+      value: 'Ready',
+      onConfirm: () => onOpenBoss('yian-kut-ku'),
+    },
+    {
+      key: 'queue',
+      label: 'Dungeon Queue',
+      detail: 'Future matchmaking shell for multi-boss dungeon routes.',
+      value: 'Planned',
+      onConfirm: () => {},
+    },
+  ], [onOpenBoss])
+
+  return (
+    <Iwt2ScreenShell title="Dungeons" onBack={onBack}>
+      <Iwt2ActionList actions={actions} />
+    </Iwt2ScreenShell>
+  )
+}
+
+export function Iwt2ModePlaceholderScreen({
+  mode,
+  onBack,
+}: {
+  mode: 'Raids' | 'Roguelike' | 'PvP'
+  onBack: () => void
+}) {
+  const actions = useMemo<Iwt2NavAction[]>(() => [
+    {
+      key: 'status',
+      label: `${mode} Prototype`,
+      detail: MODE_DESCRIPTIONS[mode],
+      value: 'Shell',
+      onConfirm: () => {},
+    },
+  ], [mode])
+
+  return (
+    <Iwt2ScreenShell title={mode} onBack={onBack}>
+      <Iwt2ActionList actions={actions} />
+    </Iwt2ScreenShell>
+  )
+}
+
+export function Iwt2HunterProfileScreen({
+  onBack,
+  save,
+}: {
+  onBack: () => void
+  save: Iwt2Save
+}) {
+  const bulldromeKills = save.collectionLog.bossKills.bulldrome ?? 0
+  const yianKills = save.collectionLog.bossKills['yian-kut-ku'] ?? 0
+  const bulldromeDrops = save.collectionLog.dropsFound['raw-bulldrome-coin'] ?? 0
+  const yianDrops = save.collectionLog.dropsFound['yian-kut-ku-scale'] ?? 0
+
+  return (
+    <Iwt2ScreenShell title="Hunter Profile" onBack={onBack}>
+      <div className="iwt2-profile-grid">
+        <div className="iwt2-list-panel">
+          <div className="iwt2-list-row">
+            <strong>Name</strong>
+            <span>{save.character.name}</span>
+          </div>
+          <div className="iwt2-list-row">
+            <strong>Level</strong>
+            <span>{save.character.level}</span>
+          </div>
+          <div className="iwt2-list-row">
+            <strong>Experience</strong>
+            <span>{save.character.experience} XP</span>
+          </div>
+        </div>
+        <div className="iwt2-list-panel">
+          <div className="iwt2-list-row">
+            <strong>Bulldrome Kills</strong>
+            <span>{bulldromeKills}</span>
+          </div>
+          <div className="iwt2-list-row">
+            <strong>Raw Bulldrome Coins</strong>
+            <span>{bulldromeDrops}</span>
+          </div>
+          <div className="iwt2-list-row">
+            <strong>Yian Kut Ku Kills</strong>
+            <span>{yianKills}</span>
+          </div>
+          <div className="iwt2-list-row">
+            <strong>Yian Kut Ku Scales</strong>
+            <span>{yianDrops}</span>
+          </div>
+          <div className="iwt2-list-row">
+            <strong>IWT2 Inventory</strong>
+            <span>{save.inventory.length} slots</span>
+          </div>
+        </div>
+      </div>
+    </Iwt2ScreenShell>
+  )
+}
+
+export function Iwt2CustomizeCharacterScreen({
+  onBack,
+  save,
+}: {
+  onBack: () => void
+  save: Iwt2Save
+}) {
+  const actions = useMemo<Iwt2NavAction[]>(() => [
+    {
+      key: 'class',
+      label: 'Healer Style',
+      detail: 'Current vertical slice uses Field Medic abilities based on IWT1 dungeon spells.',
+      value: 'Field Medic',
+      onConfirm: () => {},
+    },
+    {
+      key: 'appearance',
+      label: 'Armor Palette',
+      detail: 'Character cosmetics will stay scoped to IWT2 save data.',
+      value: 'Default',
+      onConfirm: () => {},
+    },
+    {
+      key: 'name',
+      label: 'Character Name',
+      detail: 'Name editing shell for the IWT2 hunter profile.',
+      value: save.character.name,
+      onConfirm: () => {},
+    },
+  ], [save.character.name])
+
+  return (
+    <Iwt2ScreenShell title="Customize Character" onBack={onBack}>
+      <Iwt2ActionList actions={actions} />
+    </Iwt2ScreenShell>
+  )
+}
+
+export function Iwt2CloudSaveScreen({
+  onBack,
+  save,
+}: {
+  onBack: () => void
+  save: Iwt2Save
+}) {
+  const savedAt = new Date(save.updatedAt).toLocaleString()
+  const actions = useMemo<Iwt2NavAction[]>(() => [
+    {
+      key: 'status',
+      label: 'Cloud Save Slot',
+      detail: 'Local IWT2 save is isolated and ready for cloud sync integration.',
+      value: 'Not linked',
+      onConfirm: () => {},
+    },
+    {
+      key: 'last-save',
+      label: 'Last Local Save',
+      detail: savedAt,
+      value: 'Local',
+      onConfirm: () => {},
+    },
+  ], [savedAt])
+
+  return (
+    <Iwt2ScreenShell title="Cloud Save" onBack={onBack}>
+      <Iwt2ActionList actions={actions} />
+    </Iwt2ScreenShell>
+  )
+}
+
+export function Iwt2SettingsScreen({ onBack }: { onBack: () => void }) {
+  const {
+    controllerIconStyle,
+    directPartyTargeting,
+    setControllerIconStyle,
+    setDirectPartyTargeting,
+  } = useInput()
+  const actions = useMemo<Iwt2NavAction[]>(() => [
+    {
+      key: 'direct-targeting',
+      label: 'Target Party Members With Bindings',
+      detail: 'When enabled, party frames show direct target button icons instead of D-pad cycling.',
+      value: directPartyTargeting ? 'On' : 'Off',
+      onConfirm: () => setDirectPartyTargeting(!directPartyTargeting),
+    },
+    ...CONTROLLER_ICON_OPTIONS.map((style) => ({
+      key: `icons-${style}`,
+      label: `${CONTROLLER_ICON_LABELS[style]} Button Icons`,
+      detail: 'Changes controller glyphs shown on IWT2 frames and spell controls.',
+      value: controllerIconStyle === style ? 'Selected' : '',
+      onConfirm: () => setControllerIconStyle(style),
+    })),
+  ], [
+    controllerIconStyle,
+    directPartyTargeting,
+    setControllerIconStyle,
+    setDirectPartyTargeting,
+  ])
+
+  return (
+    <Iwt2ScreenShell title="Settings" onBack={onBack}>
+      <div className="iwt2-settings-panel">
+        <Iwt2ActionList actions={actions} />
+        <div className="iwt2-controller-preview" aria-label="Current controller icon style">
+          <span>{CONTROLLER_ICON_LABELS[controllerIconStyle]}</span>
+          <ControllerStylePreview iconStyle={controllerIconStyle} />
+        </div>
+      </div>
+    </Iwt2ScreenShell>
+  )
+}

src/modes/iwt2/sim/arena.ts

@@ -0,0 +1,646 @@
+import { IWT2_BOSS_METADATA, type Iwt2BossId } from '../content/bosses'
+import { IWT2_CLASS_METADATA } from '../content/classes'
+import type {
+  Iwt2ArenaEvent,
+  Iwt2ArenaInput,
+  Iwt2ArenaState,
+  Iwt2EntityId,
+  Iwt2GroundHazardState,
+  Iwt2HostileAddState,
+  Iwt2PartyAiRole,
+  Iwt2PartyEntityId,
+  Iwt2PartyEntityState,
+  Iwt2ProjectileEntityState,
+  Iwt2StatusState,
+} from './types'
+import type { Iwt2PlayerClassId } from '../content/classes'
+import { tickBoss } from './bossAi'
+import { separateCircles } from './collision'
+import { canPartyMemberHitTarget, tickPartyMember } from './partyAi'
+import { addFirePuddle, createHazardIndicators, tickGroundHazards } from './hazards'
+import { applyPartyDamageInShape } from './mechanics'
+import {
+  clampVec2ToArena,
+  distanceVec2,
+  normalizeVec2,
+  scaleVec2,
+  subtractVec2,
+} from './vector'
+
+const DEFAULT_ARENA_WIDTH = 960
+const DEFAULT_ARENA_HEIGHT = 540
+const MAX_DT = 1 / 15
+const MAX_EVENTS = 80
+const HEALER_MANA_REGEN_PER_SECOND = 3
+const BOSS_PROJECTILE_BOUNCE_COOLDOWN_SECONDS = 0.22
+
+type InitialPartyMember = {
+  id: Iwt2PartyEntityId
+  classId: Iwt2PlayerClassId
+  aiRole: Iwt2PartyAiRole
+  x: number
+  y: number
+  preferredOffset: { x: number; y: number }
+  decisionOffset: number
+}
+
+const INITIAL_PARTY: InitialPartyMember[] = [
+  { id: 'player-healer', classId: 'healer', aiRole: 'player', x: 250, y: 250, preferredOffset: { x: -260, y: 0 }, decisionOffset: 0 },
+  { id: 'paladin-tank', classId: 'paladin', aiRole: 'tank', x: 470, y: 250, preferredOffset: { x: -58, y: 6 }, decisionOffset: 0.08 },
+  { id: 'ranger', classId: 'ranger', aiRole: 'ranged', x: 280, y: 140, preferredOffset: { x: -230, y: -92 }, decisionOffset: 0.18 },
+  { id: 'mage', classId: 'mage', aiRole: 'ranged', x: 300, y: 365, preferredOffset: { x: -190, y: 98 }, decisionOffset: 0.32 },
+  { id: 'rogue', classId: 'rogue', aiRole: 'flanker', x: 520, y: 195, preferredOffset: { x: 24, y: -58 }, decisionOffset: 0.12 },
+  { id: 'warrior', classId: 'warrior', aiRole: 'melee', x: 515, y: 310, preferredOffset: { x: -18, y: 64 }, decisionOffset: 0.24 },
+]
+
+export function createInitialIwt2ArenaState(bossId: Iwt2BossId = 'bulldrome'): Iwt2ArenaState {
+  const bossMetadata = IWT2_BOSS_METADATA[bossId]
+  return {
+    schemaVersion: 1,
+    time: 0,
+    bounds: { width: DEFAULT_ARENA_WIDTH, height: DEFAULT_ARENA_HEIGHT },
+    party: INITIAL_PARTY.map(createPartyMember),
+    projectiles: [],
+    hostileAdds: [],
+    hazards: [],
+    indicators: [],
+    boss: {
+      id: bossId,
+      kind: 'boss',
+      bossId,
+      position: { x: 640, y: 250 },
+      velocity: { x: 0, y: 0 },
+      facing: { x: -1, y: 0 },
+      radius: bossMetadata.radius,
+      health: bossMetadata.maxHealth,
+      maxHealth: bossMetadata.maxHealth,
+      meleeCooldownRemaining: 0.6,
+      chargeCooldownRemaining: bossId === 'bulldrome' ? 2 : 0,
+      chargeCount: 0,
+      attackPhase: 'idle',
+      phaseSecondsRemaining: 0,
+      chargeStart: { x: 640, y: 250 },
+      chargeEnd: { x: 640, y: 250 },
+      chargeHitEntityIds: [],
+      slamApplied: false,
+      wallContactSeconds: 0,
+      relocateTarget: { x: DEFAULT_ARENA_WIDTH * 0.58, y: DEFAULT_ARENA_HEIGHT * 0.5 },
+      fireballCooldownRemaining: bossId === 'yian-kut-ku' ? 1.2 : 0,
+      fireballTarget: { x: 320, y: 250 },
+      birdWaveThresholdsTriggered: [],
+    },
+    nextEventId: 1,
+    nextProjectileId: 1,
+    nextAddId: 1,
+    nextHazardId: 1,
+    events: [],
+  }
+}
+
+export function tickIwt2Arena(state: Iwt2ArenaState, input: Iwt2ArenaInput, dt: number): Iwt2ArenaState {
+  const step = Math.max(0, Math.min(dt, MAX_DT))
+  if (step <= 0) return { ...state, events: [...state.events] }
+
+  const inputMove = {
+    x: clampInputAxis(input.moveX),
+    y: clampInputAxis(input.moveY),
+  }
+  const baseState = {
+    ...state,
+    time: state.time + step,
+    party: state.party.map((member) => tickPartyMember(member, state, inputMove, step)),
+    events: [],
+  }
+  const separatedState = {
+    ...baseState,
+    party: separatePartyFromBoss(baseState.party, baseState),
+  }
+  const bossResult = tickBoss(separatedState, step)
+  const projectileResult = advanceProjectiles(
+    [...separatedState.projectiles, ...(bossResult.projectiles ?? [])],
+    bossResult.party,
+    bossResult.boss,
+    bossResult.hostileAdds ?? separatedState.hostileAdds,
+    bossResult.hazards ?? separatedState.hazards,
+    bossResult.nextHazardId ?? state.nextHazardId,
+    bossResult.nextProjectileId ?? state.nextProjectileId,
+    separatedState.bounds,
+    separatedState.time,
+    step,
+  )
+  const hazardResult = tickGroundHazards({
+    dt: step,
+    hazards: projectileResult.hazards,
+    party: projectileResult.party,
+    time: separatedState.time,
+  })
+  const damageResult = applyPartyAttacks(
+    hazardResult.party,
+    projectileResult.boss,
+    projectileResult.hostileAdds,
+    separatedState.time,
+    projectileResult.nextProjectileId,
+  )
+  const hotResult = tickPartyHotEffects(damageResult.party, step, separatedState.time)
+  const finalParty = regeneratePartyMana(hotResult.party, step)
+  const nextEvents = assignEventIds(
+    [...bossResult.events, ...projectileResult.events, ...hazardResult.events, ...damageResult.events, ...hotResult.events],
+    state.nextEventId,
+  )
+  return {
+    ...separatedState,
+    boss: damageResult.boss,
+    indicators: [...bossResult.indicators, ...createHazardIndicators(hazardResult.hazards)],
+    party: finalParty,
+    hostileAdds: damageResult.hostileAdds,
+    hazards: hazardResult.hazards,
+    projectiles: [...projectileResult.projectiles, ...damageResult.projectiles],
+    nextProjectileId: damageResult.nextProjectileId,
+    nextAddId: bossResult.nextAddId ?? state.nextAddId,
+    nextHazardId: projectileResult.nextHazardId,
+    nextEventId: state.nextEventId + nextEvents.length,
+    events: [...state.events, ...nextEvents].slice(-MAX_EVENTS),
+  }
+}
+
+function tickPartyHotEffects(
+  party: Iwt2PartyEntityState[],
+  dt: number,
+  time: number,
+): { party: Iwt2PartyEntityState[], events: Iwt2ArenaEvent[] } {
+  const events: Iwt2ArenaEvent[] = []
+  const nextParty = party.map((member) => {
+    if (member.hotEffects.length === 0) return member
+
+    let health = member.health
+    const hotEffects = member.hotEffects.flatMap((effect) => {
+      const remainingSeconds = effect.remainingSeconds - dt
+      if (remainingSeconds <= 0) return []
+      let nextTickInSeconds = effect.nextTickInSeconds - dt
+      if (member.health > 0 && nextTickInSeconds <= 0) {
+        const before = health
+        health = Math.min(member.maxHealth, health + effect.power)
+        const healed = health - before
+        if (healed > 0) {
+          events.push({
+            id: 0,
+            time,
+            type: 'partyHealed',
+            sourceId: 'player-healer',
+            targetId: member.id,
+            value: healed,
+          })
+        }
+        nextTickInSeconds += effect.tickIntervalSeconds
+      }
+      return [{
+        ...effect,
+        nextTickInSeconds,
+        remainingSeconds,
+      }]
+    })
+
+    return {
+      ...member,
+      health,
+      hotEffects,
+    }
+  })
+  return { party: nextParty, events }
+}
+
+function regeneratePartyMana(party: Iwt2PartyEntityState[], dt: number): Iwt2PartyEntityState[] {
+  return party.map((member) => {
+    if (member.maxMana <= 0 || member.health <= 0 || member.mana >= member.maxMana) return member
+    return {
+      ...member,
+      mana: Math.min(member.maxMana, member.mana + HEALER_MANA_REGEN_PER_SECOND * dt),
+    }
+  })
+}
+
+function createPartyMember(initial: InitialPartyMember): Iwt2PartyEntityState {
+  const metadata = IWT2_CLASS_METADATA[initial.classId]
+  return {
+    id: initial.id,
+    kind: 'party',
+    classId: initial.classId,
+    aiRole: initial.aiRole,
+    position: { x: initial.x, y: initial.y },
+    velocity: { x: 0, y: 0 },
+    facing: { x: 1, y: 0 },
+    radius: metadata.radius,
+    health: metadata.maxHealth,
+    maxHealth: metadata.maxHealth,
+    shield: 0,
+    mana: initial.classId === 'healer' ? 100 : 0,
+    maxMana: initial.classId === 'healer' ? 100 : 0,
+    damageDone: 0,
+    attackCooldownRemaining: initial.classId === 'healer' ? 0 : metadata.attackCooldown * 0.35,
+    castSecondsRemaining: 0,
+    attackReady: false,
+    status: createEmptyStatus(),
+    hotEffects: [],
+    preferredOffset: { ...initial.preferredOffset },
+    decisionSecondsRemaining: initial.decisionOffset,
+  }
+}
+
+function createEmptyStatus(): Iwt2StatusState {
+  return {
+    stunnedSeconds: 0,
+    knockedDownSeconds: 0,
+    invulnerableSeconds: 0,
+  }
+}
+
+function clampInputAxis(value: number): number {
+  if (!Number.isFinite(value)) return 0
+  return Math.min(1, Math.max(-1, value))
+}
+
+function separatePartyFromBoss(party: Iwt2PartyEntityState[], state: Iwt2ArenaState): Iwt2PartyEntityState[] {
+  return party.map((member) => {
+    if (member.health <= 0) return member
+    const position = separateCircles(
+      { position: member.position, radius: member.radius },
+      { position: state.boss.position, radius: state.boss.radius },
+      state.bounds,
+    )
+    return { ...member, position }
+  })
+}
+
+function advanceProjectiles(
+  projectiles: Iwt2ProjectileEntityState[],
+  party: Iwt2PartyEntityState[],
+  boss: Iwt2ArenaState['boss'],
+  hostileAdds: Iwt2HostileAddState[],
+  hazards: Iwt2GroundHazardState[],
+  nextHazardId: number,
+  nextProjectileId: number,
+  bounds: Iwt2ArenaState['bounds'],
+  time: number,
+  dt: number,
+): {
+  boss: Iwt2ArenaState['boss']
+  party: Iwt2PartyEntityState[]
+  hostileAdds: Iwt2HostileAddState[]
+  hazards: Iwt2GroundHazardState[]
+  nextHazardId: number
+  nextProjectileId: number
+  projectiles: Iwt2ProjectileEntityState[]
+  events: Iwt2ArenaEvent[]
+} {
+  const events: Iwt2ArenaEvent[] = []
+  let nextBoss = boss
+  let nextParty = party
+  let nextHostileAdds = hostileAdds
+  let nextHazards = hazards
+  let nextHazardIdValue = nextHazardId
+  const nextProjectiles: Iwt2ProjectileEntityState[] = []
+
+  for (const projectile of projectiles) {
+    if (projectile.owner === 'boss') {
+      const result = advanceBossProjectile({
+        bounds,
+        dt,
+        hazards: nextHazards,
+        nextHazardId: nextHazardIdValue,
+        party: nextParty,
+        projectile,
+        time,
+      })
+      nextParty = result.party
+      nextHazards = result.hazards
+      nextHazardIdValue = result.nextHazardId
+      events.push(...result.events)
+      if (result.projectile) nextProjectiles.push(result.projectile)
+      continue
+    }
+
+    if (nextBoss.health <= 0 && nextHostileAdds.every((add) => add.health <= 0)) continue
+    const nextPosition = {
+      x: projectile.position.x + projectile.velocity.x * dt,
+      y: projectile.position.y + projectile.velocity.y * dt,
+    }
+    const remainingSeconds = projectile.remainingSeconds - dt
+    const hitAdd = nextHostileAdds.find((add) => (
+      add.health > 0
+      && distanceVec2(nextPosition, add.position) <= add.radius + projectile.radius
+    ))
+    if (remainingSeconds <= 0) continue
+    if (hitAdd) {
+      const damage = Math.min(projectile.damage, hitAdd.health)
+      nextHostileAdds = nextHostileAdds.map((add) => add.id === hitAdd.id
+        ? { ...add, health: Math.max(0, add.health - damage) }
+        : add)
+      nextParty = addDamageDone(nextParty, projectile.sourceId, damage)
+      events.push({
+        id: 0,
+        time,
+        type: 'bossDamaged',
+        sourceId: projectile.sourceId,
+        targetId: hitAdd.id,
+        value: damage,
+      })
+      if (hitAdd.health - damage <= 0) {
+        events.push({
+          id: 0,
+          time,
+          type: 'entityDefeated',
+          sourceId: projectile.sourceId,
+          targetId: hitAdd.id,
+        })
+      }
+      continue
+    }
+
+    if (distanceVec2(nextPosition, nextBoss.position) <= nextBoss.radius + projectile.radius) {
+      const damage = Math.min(projectile.damage, nextBoss.health)
+      nextBoss = {
+        ...nextBoss,
+        health: Math.max(0, nextBoss.health - damage),
+      }
+      nextParty = addDamageDone(nextParty, projectile.sourceId, damage)
+      events.push({
+        id: 0,
+        time,
+        type: 'bossDamaged',
+        sourceId: projectile.sourceId,
+        targetId: nextBoss.id,
+        value: damage,
+      })
+      if (nextBoss.health <= 0) {
+        events.push({
+          id: 0,
+          time,
+          type: 'entityDefeated',
+          sourceId: projectile.sourceId,
+          targetId: nextBoss.id,
+        })
+      }
+      continue
+    }
+    nextProjectiles.push({
+      ...projectile,
+      position: nextPosition,
+      remainingSeconds,
+    })
+  }
+
+  return {
+    boss: nextBoss,
+    party: nextParty,
+    hostileAdds: nextHostileAdds,
+    hazards: nextHazards,
+    nextHazardId: nextHazardIdValue,
+    nextProjectileId,
+    projectiles: nextProjectiles,
+    events,
+  }
+}
+
+function advanceBossProjectile({
+  bounds,
+  dt,
+  hazards,
+  nextHazardId,
+  party,
+  projectile,
+  time,
+}: {
+  bounds: Iwt2ArenaState['bounds']
+  dt: number
+  hazards: Iwt2GroundHazardState[]
+  nextHazardId: number
+  party: Iwt2PartyEntityState[]
+  projectile: Iwt2ProjectileEntityState
+  time: number
+}): {
+  party: Iwt2PartyEntityState[]
+  hazards: Iwt2GroundHazardState[]
+  nextHazardId: number
+  projectile?: Iwt2ProjectileEntityState
+  events: Iwt2ArenaEvent[]
+} {
+  const events: Iwt2ArenaEvent[] = []
+  const remainingSeconds = projectile.remainingSeconds - dt
+  if (remainingSeconds <= 0) return { party, hazards, nextHazardId, events }
+
+  let nextParty = party
+  let nextHazards = hazards
+  let nextHazardIdValue = nextHazardId
+  let bounced = false
+  const bounceCooldownSeconds = Math.max(0, (projectile.bounceCooldownSeconds ?? 0) - dt)
+  const canBounce = bounceCooldownSeconds <= 0
+  let velocity = { ...projectile.velocity }
+  let position = {
+    x: projectile.position.x + projectile.velocity.x * dt,
+    y: projectile.position.y + projectile.velocity.y * dt,
+  }
+
+  if (canBounce && (position.x - projectile.radius <= 0 || position.x + projectile.radius >= bounds.width)) {
+    velocity = { ...velocity, x: -velocity.x }
+    position = clampVec2ToArena(position, projectile.radius, bounds)
+    bounced = true
+  }
+  if (canBounce && (position.y - projectile.radius <= 0 || position.y + projectile.radius >= bounds.height)) {
+    velocity = { ...velocity, y: -velocity.y }
+    position = clampVec2ToArena(position, projectile.radius, bounds)
+    bounced = true
+  }
+
+  const hitMember = canBounce
+    ? nextParty.find((member) => (
+      member.health > 0
+      && distanceVec2(position, member.position) <= projectile.radius + member.radius
+    ))
+    : undefined
+  if (hitMember) {
+    const result = applyPartyDamageInShape(nextParty, {
+      kind: 'circle',
+      position: hitMember.position,
+      radius: hitMember.radius + projectile.radius,
+    }, {
+      damage: projectile.damage,
+      sourceId: projectile.sourceId,
+      time,
+    })
+    nextParty = result.party
+    events.push(...result.events)
+    const away = normalizeVec2(subtractVec2(position, hitMember.position))
+    const fallback = normalizeVec2(scaleVec2(projectile.velocity, -1))
+    const direction = away.x === 0 && away.y === 0 ? fallback : away
+    const speed = Math.max(1, Math.hypot(projectile.velocity.x, projectile.velocity.y))
+    velocity = scaleVec2(direction, speed)
+    position = clampVec2ToArena({
+      x: hitMember.position.x + direction.x * (hitMember.radius + projectile.radius + 2),
+      y: hitMember.position.y + direction.y * (hitMember.radius + projectile.radius + 2),
+    }, projectile.radius, bounds)
+    bounced = true
+  }
+
+  if (bounced) {
+    const puddle = addFirePuddle({
+      damage: IWT2_BOSS_METADATA['yian-kut-ku'].firePuddleDamage!,
+      duration: IWT2_BOSS_METADATA['yian-kut-ku'].firePuddleSeconds!,
+      hazards: nextHazards,
+      nextHazardId: nextHazardIdValue,
+      position: hitMember?.position ?? position,
+      radius: IWT2_BOSS_METADATA['yian-kut-ku'].firePuddleRadius!,
+      sourceId: projectile.sourceId,
+      time,
+    })
+    nextHazards = puddle.hazards
+    nextHazardIdValue = puddle.nextHazardId
+  }
+
+  const bouncesRemaining = bounced
+    ? (projectile.bouncesRemaining ?? 0) - 1
+    : projectile.bouncesRemaining
+  if (bouncesRemaining !== undefined && bouncesRemaining < 0) {
+    return { party: nextParty, hazards: nextHazards, nextHazardId: nextHazardIdValue, events }
+  }
+
+  return {
+    events,
+    hazards: nextHazards,
+    nextHazardId: nextHazardIdValue,
+    party: nextParty,
+    projectile: {
+      ...projectile,
+      bouncesRemaining,
+      bounceCooldownSeconds: bounced ? BOSS_PROJECTILE_BOUNCE_COOLDOWN_SECONDS : bounceCooldownSeconds,
+      position,
+      remainingSeconds,
+      velocity,
+    },
+  }
+}
+
+function applyPartyAttacks(
+  party: Iwt2PartyEntityState[],
+  boss: Iwt2ArenaState['boss'],
+  hostileAdds: Iwt2HostileAddState[],
+  time: number,
+  nextProjectileId: number,
+): {
+  boss: Iwt2ArenaState['boss']
+  party: Iwt2PartyEntityState[]
+  hostileAdds: Iwt2HostileAddState[]
+  projectiles: Iwt2ProjectileEntityState[]
+  nextProjectileId: number
+  events: Iwt2ArenaEvent[]
+} {
+  const events: Iwt2ArenaEvent[] = []
+  const projectiles: Iwt2ProjectileEntityState[] = []
+  let nextBoss = boss
+  let nextHostileAdds = hostileAdds
+  let projectileId = nextProjectileId
+  const nextParty = party.map((member) => {
+    const target = getPriorityAttackTarget(member, nextBoss, nextHostileAdds)
+    if (!target) return member
+    if (!canPartyMemberHitTarget(member, target.position)) return member
+    const metadata = IWT2_CLASS_METADATA[member.classId]
+    if (metadata.projectileSpeed > 0) {
+      if (!member.attackReady) return member
+      const direction = normalizeVec2(subtractVec2(target.position, member.position))
+      projectiles.push({
+        id: `projectile-${projectileId}`,
+        sourceId: member.id,
+        owner: 'party',
+        classId: member.classId,
+        projectileKind: member.classId === 'mage' ? 'magic' : 'arrow',
+        color: metadata.accentColor,
+        position: {
+          x: member.position.x + direction.x * (member.radius + 4),
+          y: member.position.y + direction.y * (member.radius + 4),
+        },
+        velocity: scaleVec2(direction, metadata.projectileSpeed),
+        radius: member.classId === 'mage' ? 7 : 4,
+        damage: metadata.attackDamage,
+        remainingSeconds: 1.2,
+      })
+      projectileId += 1
+      return {
+        ...member,
+        attackCooldownRemaining: metadata.attackCooldown,
+        attackReady: false,
+      }
+    }
+    if (member.attackCooldownRemaining > 0) return member
+    const damage = Math.min(metadata.attackDamage, target.health)
+    if (target.kind === 'boss') {
+      nextBoss = { ...nextBoss, health: Math.max(0, nextBoss.health - damage) }
+    } else {
+      nextHostileAdds = nextHostileAdds.map((add) => add.id === target.id
+        ? { ...add, health: Math.max(0, add.health - damage) }
+        : add)
+    }
+    events.push({
+      id: 0,
+      time,
+      type: 'bossDamaged',
+      sourceId: member.id,
+      targetId: target.id,
+      value: damage,
+    })
+    if (target.health - damage <= 0) {
+      events.push({
+        id: 0,
+        time,
+        type: 'entityDefeated',
+        sourceId: member.id,
+        targetId: target.id,
+      })
+      return {
+        ...member,
+        damageDone: member.damageDone + damage,
+        attackCooldownRemaining: metadata.attackCooldown,
+      }
+    }
+    return {
+      ...member,
+      damageDone: member.damageDone + damage,
+      attackCooldownRemaining: metadata.attackCooldown,
+    }
+  })
+  return {
+    boss: nextBoss,
+    party: nextParty,
+    hostileAdds: nextHostileAdds.filter((add) => add.health > 0),
+    projectiles,
+    nextProjectileId: projectileId,
+    events,
+  }
+}
+
+function getPriorityAttackTarget(
+  member: Iwt2PartyEntityState,
+  boss: Iwt2ArenaState['boss'],
+  hostileAdds: Iwt2HostileAddState[],
+): (Iwt2ArenaState['boss'] | Iwt2HostileAddState) | undefined {
+  if (member.health <= 0) return undefined
+  const livingAdds = hostileAdds.filter((add) => add.health > 0)
+  if (livingAdds.length > 0) {
+    return livingAdds.reduce((best, add) => (
+      distanceVec2(member.position, add.position) < distanceVec2(member.position, best.position) ? add : best
+    ), livingAdds[0])
+  }
+  return boss.health > 0 ? boss : undefined
+}
+
+function addDamageDone(
+  party: Iwt2PartyEntityState[],
+  sourceId: Iwt2EntityId,
+  damage: number,
+): Iwt2PartyEntityState[] {
+  return party.map((member) => member.id === sourceId
+    ? { ...member, damageDone: member.damageDone + damage }
+    : member)
+}
+
+function assignEventIds(events: Iwt2ArenaEvent[], firstId: number): Iwt2ArenaEvent[] {
+  return events.map((event, index) => ({ ...event, id: firstId + index }))
+}

src/modes/iwt2/sim/arenaState.ts

@@ -0,0 +1,148 @@
+import { IWT2_BOSS_METADATA, type Iwt2BossId } from '../content/bosses'
+import { IWT2_CLASS_METADATA } from '../content/classes'
+import {
+  createInitialIwt2ArenaState as createCoreIwt2ArenaState,
+  tickIwt2Arena as tickCoreIwt2Arena,
+} from './arena'
+import type {
+  Iwt2ArenaIndicator,
+  Iwt2ArenaInput,
+  Iwt2ArenaState as Iwt2CoreArenaState,
+  Iwt2BossEntityState,
+  Iwt2HostileAddState,
+  Iwt2PartyEntityState,
+} from './types'
+
+export type Iwt2ArenaEntityKind = 'player' | 'party' | 'boss' | 'projectile' | 'hostileAdd'
+
+export type Iwt2ArenaEntity = {
+  id: string
+  kind: Iwt2ArenaEntityKind
+  icon: string
+  color: string
+  x: number
+  y: number
+  radius: number
+  health: number
+  maxHealth: number
+  stunnedFor: number
+}
+
+export type Iwt2ArenaTelegraph =
+  | {
+    kind: 'charge'
+    x: number
+    y: number
+    width: number
+    height: number
+    active: boolean
+  }
+  | {
+    kind: 'slam'
+    x: number
+    y: number
+    radius: number
+    active: boolean
+  }
+
+export type Iwt2ArenaState = Iwt2CoreArenaState & {
+  arena: {
+    width: number
+    height: number
+  }
+  entities: Iwt2ArenaEntity[]
+  telegraphs: Iwt2ArenaTelegraph[]
+}
+
+export function createInitialIwt2ArenaState(bossId?: Iwt2BossId): Iwt2ArenaState {
+  return decorateArenaState(createCoreIwt2ArenaState(bossId))
+}
+
+export function tickIwt2Arena(state: Iwt2ArenaState, input: Iwt2ArenaInput, dt: number): Iwt2ArenaState {
+  return decorateArenaState(tickCoreIwt2Arena(state, input, dt))
+}
+
+export function decorateArenaState(state: Iwt2CoreArenaState): Iwt2ArenaState {
+  return {
+    ...state,
+    arena: { ...state.bounds },
+    entities: [
+      ...state.party.map(toArenaEntity),
+      ...state.hostileAdds.map(toHostileAddArenaEntity),
+      toBossArenaEntity(state.boss),
+    ],
+    telegraphs: createTelegraphs(state.indicators),
+  }
+}
+
+function toHostileAddArenaEntity(add: Iwt2HostileAddState): Iwt2ArenaEntity {
+  return {
+    id: add.id,
+    kind: 'hostileAdd',
+    icon: 'v',
+    color: '#f0b84f',
+    x: add.position.x,
+    y: add.position.y,
+    radius: add.radius,
+    health: add.health,
+    maxHealth: add.maxHealth,
+    stunnedFor: 0,
+  }
+}
+
+function toArenaEntity(member: Iwt2PartyEntityState): Iwt2ArenaEntity {
+  const metadata = IWT2_CLASS_METADATA[member.classId]
+  return {
+    id: member.id,
+    kind: member.aiRole === 'player' ? 'player' : 'party',
+    icon: metadata.icon,
+    color: metadata.color,
+    x: member.position.x,
+    y: member.position.y,
+    radius: member.radius,
+    health: member.health,
+    maxHealth: member.maxHealth,
+    stunnedFor: Math.max(member.status.stunnedSeconds, member.status.knockedDownSeconds),
+  }
+}
+
+function toBossArenaEntity(boss: Iwt2BossEntityState): Iwt2ArenaEntity {
+  const metadata = IWT2_BOSS_METADATA[boss.bossId]
+  return {
+    id: boss.id,
+    kind: 'boss',
+    icon: metadata.icon,
+    color: metadata.color,
+    x: boss.position.x,
+    y: boss.position.y,
+    radius: boss.radius,
+    health: boss.health,
+    maxHealth: boss.maxHealth,
+    stunnedFor: 0,
+  }
+}
+
+function createTelegraphs(indicators: Iwt2ArenaIndicator[]): Iwt2ArenaTelegraph[] {
+  return indicators.flatMap((indicator): Iwt2ArenaTelegraph[] => {
+    if (indicator.kind === 'lane') {
+      return [{
+        active: indicator.phase === 'active',
+        height: indicator.width * 2,
+        kind: 'charge' as const,
+        width: Math.max(16, Math.hypot(indicator.end.x - indicator.start.x, indicator.end.y - indicator.start.y)),
+        x: Math.min(indicator.start.x, indicator.end.x),
+        y: Math.min(indicator.start.y, indicator.end.y) - indicator.width,
+      }]
+    }
+    if (indicator.kind === 'circle') {
+      return [{
+        active: indicator.phase === 'active',
+        kind: 'slam' as const,
+        radius: indicator.radius,
+        x: indicator.position.x,
+        y: indicator.position.y,
+      }]
+    }
+    return []
+  })
+}

src/modes/iwt2/sim/bossAi.ts

@@ -0,0 +1,378 @@
+import { BULLDROME_BOSS_METADATA } from '../content/bosses'
+import type {
+  Iwt2ArenaEvent,
+  Iwt2ArenaIndicator,
+  Iwt2ArenaState,
+  Iwt2BossEntityState,
+  Iwt2EntityId,
+  Iwt2GroundHazardState,
+  Iwt2HostileAddState,
+  Iwt2PartyEntityState,
+  Iwt2ProjectileEntityState,
+  Iwt2Vec2,
+} from './types'
+import { tickYianKutKu } from './yianKutKuAi'
+import {
+  applyPartyDamageInShape,
+  createArenaEvent,
+  createCircleIndicator,
+  createLaneIndicator,
+  createLinearMovementPlan,
+  indicatorPhaseFromAttack,
+} from './mechanics'
+import {
+  clampVec2ToArena,
+  distanceVec2,
+  moveToward,
+  scaleVec2,
+  subtractVec2,
+  withFallbackFacing,
+} from './vector'
+
+export type Iwt2BossTickResult = {
+  boss: Iwt2BossEntityState
+  party: Iwt2PartyEntityState[]
+  hostileAdds?: Iwt2HostileAddState[]
+  hazards?: Iwt2GroundHazardState[]
+  projectiles?: Iwt2ProjectileEntityState[]
+  events: Iwt2ArenaEvent[]
+  indicators: Iwt2ArenaIndicator[]
+  nextAddId?: number
+  nextHazardId?: number
+  nextProjectileId?: number
+}
+
+export function tickBoss(state: Iwt2ArenaState, dt: number): Iwt2BossTickResult {
+  if (state.boss.bossId === 'yian-kut-ku') return tickYianKutKu(state, dt)
+  return tickBulldrome(state, dt)
+}
+
+export function tickBulldrome(state: Iwt2ArenaState, dt: number): Iwt2BossTickResult {
+  const events: Iwt2ArenaEvent[] = []
+  const target = getBossTarget(state.party)
+  let party = state.party
+  let boss = {
+    ...state.boss,
+    meleeCooldownRemaining: Math.max(0, state.boss.meleeCooldownRemaining - dt),
+    chargeCooldownRemaining: Math.max(0, state.boss.chargeCooldownRemaining - dt),
+    phaseSecondsRemaining: Math.max(0, state.boss.phaseSecondsRemaining - dt),
+  }
+  const wallContactSeconds = isBossNearWall(boss, state)
+    ? boss.wallContactSeconds + dt
+    : Math.max(0, boss.wallContactSeconds - dt * 2)
+  boss = { ...boss, wallContactSeconds }
+
+  if (boss.health <= 0 || !target) {
+    return withBulldromeIndicators({ boss: { ...boss, velocity: { x: 0, y: 0 } }, party, events })
+  }
+
+  if (boss.attackPhase === 'relocating') {
+    const nextPosition = clampVec2ToArena(
+      moveToward(boss.position, boss.relocateTarget, BULLDROME_BOSS_METADATA.moveSpeed * 1.45 * dt),
+      boss.radius,
+      state.bounds,
+    )
+    const velocity = scaleVec2(subtractVec2(nextPosition, boss.position), dt > 0 ? 1 / dt : 0)
+    boss = {
+      ...boss,
+      position: nextPosition,
+      velocity,
+      facing: withFallbackFacing(subtractVec2(target.position, nextPosition), boss.facing),
+      wallContactSeconds: isBossNearWall({ ...boss, position: nextPosition }, state) ? boss.wallContactSeconds : 0,
+    }
+    if (boss.phaseSecondsRemaining <= 0 || distanceVec2(nextPosition, boss.relocateTarget) <= 8) {
+      boss = {
+        ...boss,
+        attackPhase: 'idle',
+        phaseSecondsRemaining: 0,
+        chargeCooldownRemaining: Math.max(boss.chargeCooldownRemaining, 1.2),
+        velocity: { x: 0, y: 0 },
+      }
+    }
+    return withBulldromeIndicators({ boss, party, events })
+  }
+
+  if (boss.attackPhase === 'chargeWindup') {
+    boss = {
+      ...boss,
+      velocity: { x: 0, y: 0 },
+      facing: withFallbackFacing(subtractVec2(boss.chargeEnd, boss.position), boss.facing),
+    }
+    if (boss.phaseSecondsRemaining <= 0) boss = { ...boss, attackPhase: 'charging' }
+    return withBulldromeIndicators({ boss, party, events })
+  }
+
+  if (boss.attackPhase === 'charging') {
+    const nextPosition = clampVec2ToArena(
+      moveToward(boss.position, boss.chargeEnd, BULLDROME_BOSS_METADATA.chargeSpeed * dt),
+      boss.radius,
+      state.bounds,
+    )
+    const hitResult = applyChargeHits(party, boss, boss.position, nextPosition, state.time + dt)
+    party = hitResult.party
+    events.push(...hitResult.events)
+    const velocity = scaleVec2(subtractVec2(nextPosition, boss.position), dt > 0 ? 1 / dt : 0)
+    boss = {
+      ...boss,
+      position: nextPosition,
+      velocity,
+      facing: withFallbackFacing(velocity, boss.facing),
+      chargeHitEntityIds: hitResult.hitEntityIds,
+    }
+    if (distanceVec2(nextPosition, boss.chargeEnd) <= 1) {
+      const needsSlam = boss.chargeCount % 3 === 0
+      boss = {
+        ...boss,
+        attackPhase: needsSlam ? 'slamWindup' : 'chargeRecover',
+        phaseSecondsRemaining: needsSlam ? BULLDROME_BOSS_METADATA.slamWindup : 0.45,
+        slamApplied: false,
+        velocity: { x: 0, y: 0 },
+      }
+    }
+    return withBulldromeIndicators({ boss, party, events })
+  }
+
+  if (boss.attackPhase === 'slamWindup') {
+    boss = { ...boss, velocity: { x: 0, y: 0 } }
+    if (boss.phaseSecondsRemaining <= 0) {
+      const slamResult = applySlam(party, boss, state.time + dt)
+      party = slamResult.party
+      events.push(...slamResult.events)
+      boss = {
+        ...boss,
+        attackPhase: 'slamRecover',
+        phaseSecondsRemaining: 0.5,
+        slamApplied: true,
+      }
+    }
+    return withBulldromeIndicators({ boss, party, events })
+  }
+
+  if (boss.attackPhase === 'chargeRecover' || boss.attackPhase === 'slamRecover') {
+    boss = { ...boss, velocity: { x: 0, y: 0 } }
+    if (boss.phaseSecondsRemaining <= 0) {
+      boss = { ...boss, attackPhase: 'idle', phaseSecondsRemaining: 0 }
+    }
+    return withBulldromeIndicators({ boss, party, events })
+  }
+
+  if (boss.attackPhase === 'idle' && boss.wallContactSeconds >= 1.1) {
+    boss = {
+      ...boss,
+      attackPhase: 'relocating',
+      phaseSecondsRemaining: 1.8,
+      relocateTarget: relocationTarget(boss, state),
+      velocity: { x: 0, y: 0 },
+    }
+    return withBulldromeIndicators({ boss, party, events })
+  }
+
+  if (boss.chargeCooldownRemaining <= 0) {
+    const charge = createLinearMovementPlan({
+      bounds: state.bounds,
+      from: boss.position,
+      length: BULLDROME_BOSS_METADATA.chargeLength,
+      radius: boss.radius,
+      target: target.position,
+    })
+    boss = {
+      ...boss,
+      attackPhase: 'chargeWindup',
+      phaseSecondsRemaining: BULLDROME_BOSS_METADATA.chargeWindup,
+      chargeCooldownRemaining: BULLDROME_BOSS_METADATA.chargeCooldown,
+      chargeCount: boss.chargeCount + 1,
+      chargeStart: { ...boss.position },
+      chargeEnd: charge.end,
+      chargeHitEntityIds: [],
+      slamApplied: false,
+      facing: charge.direction,
+      velocity: { x: 0, y: 0 },
+    }
+    events.push(createArenaEvent(state.nextEventId + events.length, state.time + dt, 'bossChargeStart', boss.id, target.id))
+    return withBulldromeIndicators({ boss, party, events })
+  }
+
+  const meleeResult = maybeApplyMelee(party, boss, target, state.time + dt, state.nextEventId + events.length)
+  party = meleeResult.party
+  events.push(...meleeResult.events)
+  boss = meleeResult.boss
+
+  if (meleeResult.events.length > 0) return withBulldromeIndicators({ boss, party, events })
+
+  const nextPosition = clampVec2ToArena(
+    moveToward(boss.position, target.position, BULLDROME_BOSS_METADATA.moveSpeed * dt),
+    boss.radius,
+    state.bounds,
+  )
+  const velocity = scaleVec2(subtractVec2(nextPosition, boss.position), dt > 0 ? 1 / dt : 0)
+  boss = {
+    ...boss,
+    position: nextPosition,
+    velocity,
+    facing: withFallbackFacing(subtractVec2(target.position, nextPosition), boss.facing),
+  }
+  return withBulldromeIndicators({ boss, party, events })
+}
+
+function isBossNearWall(boss: Iwt2BossEntityState, state: Iwt2ArenaState) {
+  const margin = boss.radius + 10
+  return (
+    boss.position.x <= margin
+    || boss.position.x >= state.bounds.width - margin
+    || boss.position.y <= margin
+    || boss.position.y >= state.bounds.height - margin
+  )
+}
+
+function relocationTarget(boss: Iwt2BossEntityState, state: Iwt2ArenaState): Iwt2Vec2 {
+  const center = { x: state.bounds.width * 0.58, y: state.bounds.height * 0.5 }
+  const awayFromWall = {
+    x: boss.position.x < state.bounds.width * 0.5 ? 1 : -1,
+    y: boss.position.y < state.bounds.height * 0.5 ? 1 : -1,
+  }
+  return {
+    x: Math.min(state.bounds.width - boss.radius, Math.max(boss.radius, center.x + awayFromWall.x * 70)),
+    y: Math.min(state.bounds.height - boss.radius, Math.max(boss.radius, center.y + awayFromWall.y * 54)),
+  }
+}
+
+function getBossTarget(party: Iwt2PartyEntityState[]): Iwt2PartyEntityState | undefined {
+  const livingTank = party.find((member) => member.classId === 'paladin' && member.health > 0)
+  if (livingTank) return livingTank
+  return party.find((member) => member.health > 0)
+}
+
+function maybeApplyMelee(
+  party: Iwt2PartyEntityState[],
+  boss: Iwt2BossEntityState,
+  target: Iwt2PartyEntityState,
+  time: number,
+  firstEventId: number,
+): Omit<Iwt2BossTickResult, 'indicators'> {
+  if (boss.meleeCooldownRemaining > 0) return { boss, party, events: [] }
+  if (distanceVec2(boss.position, target.position) > BULLDROME_BOSS_METADATA.meleeRange + target.radius) {
+    return { boss, party, events: [] }
+  }
+  const nextParty = party.map((member) => {
+    if (member.id !== target.id) return member
+    return { ...member, health: Math.max(0, member.health - BULLDROME_BOSS_METADATA.meleeDamage) }
+  })
+  const events = [
+    createArenaEvent(firstEventId, time, 'partyDamaged', boss.id, target.id, BULLDROME_BOSS_METADATA.meleeDamage),
+  ]
+  if (target.health > 0 && target.health - BULLDROME_BOSS_METADATA.meleeDamage <= 0) {
+    events.push(createArenaEvent(firstEventId + 1, time, 'entityDefeated', boss.id, target.id))
+  }
+  return {
+    boss: { ...boss, meleeCooldownRemaining: BULLDROME_BOSS_METADATA.meleeCooldown, velocity: { x: 0, y: 0 } },
+    party: nextParty,
+    events,
+  }
+}
+
+function applyChargeHits(
+  party: Iwt2PartyEntityState[],
+  boss: Iwt2BossEntityState,
+  start: Iwt2Vec2,
+  end: Iwt2Vec2,
+  time: number,
+): { party: Iwt2PartyEntityState[], hitEntityIds: Iwt2EntityId[], events: Iwt2ArenaEvent[] } {
+  const result = applyPartyDamageInShape(
+    party,
+    {
+      kind: 'lane',
+      start,
+      end,
+      width: boss.radius,
+    },
+    {
+      damage: BULLDROME_BOSS_METADATA.chargeDamage,
+      damageEventType: 'bossChargeHit',
+      excludedEntityIds: boss.chargeHitEntityIds,
+      knockdownSeconds: BULLDROME_BOSS_METADATA.chargeStunSeconds,
+      sourceId: boss.id,
+      stunSeconds: BULLDROME_BOSS_METADATA.chargeStunSeconds,
+      time,
+    },
+  )
+  return {
+    ...result,
+    hitEntityIds: [...boss.chargeHitEntityIds, ...result.hitEntityIds],
+  }
+}
+
+function applySlam(
+  party: Iwt2PartyEntityState[],
+  boss: Iwt2BossEntityState,
+  time: number,
+): { party: Iwt2PartyEntityState[], events: Iwt2ArenaEvent[] } {
+  const result = applyPartyDamageInShape(
+    party,
+    {
+      kind: 'circle',
+      position: boss.position,
+      radius: BULLDROME_BOSS_METADATA.slamRadius,
+    },
+    {
+      damage: BULLDROME_BOSS_METADATA.slamDamage,
+      knockdownSeconds: BULLDROME_BOSS_METADATA.slamStunSeconds,
+      sourceId: boss.id,
+      stunSeconds: BULLDROME_BOSS_METADATA.slamStunSeconds,
+      time,
+    },
+  )
+  return {
+    party: result.party,
+    events: [
+      createArenaEvent(0, time, 'bossSlam', boss.id, undefined, BULLDROME_BOSS_METADATA.slamRadius),
+      ...result.events,
+    ],
+  }
+}
+
+function withBulldromeIndicators(
+  result: Omit<Iwt2BossTickResult, 'indicators'>,
+): Iwt2BossTickResult {
+  return {
+    ...result,
+    indicators: createBulldromeIndicators(result.boss),
+  }
+}
+
+function createBulldromeIndicators(boss: Iwt2BossEntityState): Iwt2ArenaIndicator[] {
+  const indicators: Iwt2ArenaIndicator[] = []
+  if (
+    boss.attackPhase === 'chargeWindup'
+    || boss.attackPhase === 'charging'
+    || boss.attackPhase === 'chargeRecover'
+  ) {
+    indicators.push(createLaneIndicator({
+      color: boss.attackPhase === 'charging' ? '#f05b4f' : '#f1c663',
+      end: boss.chargeEnd,
+      id: `${boss.id}:charge-lane`,
+      mechanicId: 'bulldrome-charge',
+      phase: indicatorPhaseFromAttack(
+        boss.attackPhase === 'chargeWindup',
+        boss.attackPhase === 'charging',
+      ),
+      sourceId: boss.id,
+      start: boss.chargeStart,
+      width: boss.radius,
+    }))
+  }
+  if (boss.attackPhase === 'slamWindup' || boss.attackPhase === 'slamRecover') {
+    indicators.push(createCircleIndicator({
+      color: '#ff7f50',
+      id: `${boss.id}:slam-circle`,
+      mechanicId: 'bulldrome-slam',
+      phase: indicatorPhaseFromAttack(
+        boss.attackPhase === 'slamWindup',
+        boss.attackPhase === 'slamRecover',
+      ),
+      position: boss.position,
+      radius: BULLDROME_BOSS_METADATA.slamRadius,
+      sourceId: boss.id,
+    }))
+  }
+  return indicators
+}

src/modes/iwt2/sim/collision.ts

@@ -0,0 +1,46 @@
+import type { Iwt2ArenaBounds, Iwt2Circle, Iwt2Vec2 } from './types'
+import {
+  addVec2,
+  clamp,
+  clampVec2ToArena,
+  distanceVec2,
+  dotVec2,
+  lengthSqVec2,
+  normalizeVec2,
+  scaleVec2,
+  subtractVec2,
+} from './vector'
+
+export function circlesOverlap(a: Iwt2Circle, b: Iwt2Circle): boolean {
+  const radiusSum = a.radius + b.radius
+  return distanceVec2(a.position, b.position) <= radiusSum
+}
+
+export function distanceToSegment(point: Iwt2Vec2, start: Iwt2Vec2, end: Iwt2Vec2): number {
+  const segment = subtractVec2(end, start)
+  const segmentLengthSq = lengthSqVec2(segment)
+  if (segmentLengthSq <= 0.0001) return distanceVec2(point, start)
+  const pointOffset = subtractVec2(point, start)
+  const t = clamp(dotVec2(pointOffset, segment) / segmentLengthSq, 0, 1)
+  const projection = addVec2(start, scaleVec2(segment, t))
+  return distanceVec2(point, projection)
+}
+
+export function circleIntersectsSegment(
+  circle: Iwt2Circle,
+  start: Iwt2Vec2,
+  end: Iwt2Vec2,
+  width: number,
+): boolean {
+  return distanceToSegment(circle.position, start, end) <= circle.radius + width
+}
+
+export function separateCircles(moving: Iwt2Circle, fixed: Iwt2Circle, bounds: Iwt2ArenaBounds): Iwt2Vec2 {
+  const offset = subtractVec2(moving.position, fixed.position)
+  const minDistance = moving.radius + fixed.radius
+  const distanceSq = lengthSqVec2(offset)
+  if (distanceSq >= minDistance * minDistance) return moving.position
+  const direction = distanceSq <= 0.0001 ? { x: 1, y: 0 } : normalizeVec2(offset)
+  const resolved = addVec2(fixed.position, scaleVec2(direction, minDistance))
+  return clampVec2ToArena(resolved, moving.radius, bounds)
+}

src/modes/iwt2/sim/hazards.ts

@@ -0,0 +1,162 @@
+import type {
+  Iwt2ArenaEvent,
+  Iwt2ArenaIndicator,
+  Iwt2EntityId,
+  Iwt2GroundHazardState,
+  Iwt2PartyEntityState,
+  Iwt2Vec2,
+} from './types'
+import {
+  applyPartyDamageInShape,
+  createCircleIndicator,
+} from './mechanics'
+
+const MAX_FIRE_PUDDLES = 8
+const FIRE_PUDDLE_TICK_SECONDS = 0.55
+const FIRE_PUDDLE_FADE_SECONDS = 0.8
+const FIRE_PUDDLE_MERGE_DISTANCE = 28
+
+export function addFirePuddle({
+  damage,
+  duration,
+  hazards,
+  nextHazardId,
+  position,
+  radius,
+  sourceId,
+  time,
+}: {
+  damage: number
+  duration: number
+  hazards: Iwt2GroundHazardState[]
+  nextHazardId: number
+  position: Iwt2Vec2
+  radius: number
+  sourceId: Iwt2EntityId
+  time: number
+}): { hazards: Iwt2GroundHazardState[], nextHazardId: number } {
+  const overlappingIndex = hazards.findIndex((hazard) => (
+    hazard.hazardKind === 'firePuddle'
+    && hazard.remainingSeconds > hazard.fadeSeconds
+    && Math.hypot(hazard.position.x - position.x, hazard.position.y - position.y) <= FIRE_PUDDLE_MERGE_DISTANCE
+  ))
+  if (overlappingIndex >= 0) {
+    return {
+      hazards: hazards.map((hazard, index) => index === overlappingIndex
+        ? {
+          ...hazard,
+          damage: Math.max(hazard.damage, damage),
+          position: {
+            x: (hazard.position.x + position.x) / 2,
+            y: (hazard.position.y + position.y) / 2,
+          },
+          radius: Math.max(hazard.radius, radius),
+          remainingSeconds: Math.max(hazard.remainingSeconds, duration),
+        }
+        : hazard),
+      nextHazardId,
+    }
+  }
+
+  const nextHazard: Iwt2GroundHazardState = {
+    id: `fire-puddle-${nextHazardId}`,
+    kind: 'groundHazard',
+    hazardKind: 'firePuddle',
+    sourceId,
+    position: { ...position },
+    radius,
+    damage,
+    remainingSeconds: duration,
+    fadeSeconds: FIRE_PUDDLE_FADE_SECONDS,
+    nextDamageAt: time + 0.12,
+  }
+  return {
+    hazards: capFirePuddles([...hazards, nextHazard]),
+    nextHazardId: nextHazardId + 1,
+  }
+}
+
+export function tickGroundHazards({
+  dt,
+  hazards,
+  party,
+  time,
+}: {
+  dt: number
+  hazards: Iwt2GroundHazardState[]
+  party: Iwt2PartyEntityState[]
+  time: number
+}): {
+  hazards: Iwt2GroundHazardState[]
+  party: Iwt2PartyEntityState[]
+  events: Iwt2ArenaEvent[]
+} {
+  const events: Iwt2ArenaEvent[] = []
+  let nextParty = party
+  const nextHazards: Iwt2GroundHazardState[] = []
+
+  for (const hazard of hazards) {
+    const remainingSeconds = hazard.remainingSeconds - dt
+    if (remainingSeconds <= 0) continue
+
+    let nextDamageAt = hazard.nextDamageAt
+    if (time >= hazard.nextDamageAt) {
+      const result = applyPartyDamageInShape(
+        nextParty,
+        {
+          kind: 'circle',
+          position: hazard.position,
+          radius: hazard.radius,
+        },
+        {
+          damage: hazard.damage,
+          sourceId: hazard.sourceId,
+          time,
+        },
+      )
+      nextParty = result.party
+      events.push(...result.events)
+      nextDamageAt = time + FIRE_PUDDLE_TICK_SECONDS
+    }
+
+    nextHazards.push({
+      ...hazard,
+      nextDamageAt,
+      remainingSeconds,
+    })
+  }
+
+  return {
+    events,
+    hazards: nextHazards,
+    party: nextParty,
+  }
+}
+
+export function createHazardIndicators(hazards: Iwt2GroundHazardState[]): Iwt2ArenaIndicator[] {
+  return hazards.map((hazard) => createCircleIndicator({
+    color: '#ff7a2f',
+    id: `${hazard.id}:indicator`,
+    mechanicId: 'fire-puddle',
+    phase: hazard.remainingSeconds <= hazard.fadeSeconds ? 'recover' : 'active',
+    position: hazard.position,
+    radius: hazard.radius,
+    sourceId: hazard.sourceId,
+  }))
+}
+
+function capFirePuddles(hazards: Iwt2GroundHazardState[]): Iwt2GroundHazardState[] {
+  let activePuddles = 0
+  let oldestActivePuddleIndex = -1
+  for (let index = 0; index < hazards.length; index += 1) {
+    const hazard = hazards[index]
+    if (hazard.hazardKind !== 'firePuddle' || hazard.remainingSeconds <= hazard.fadeSeconds) continue
+    activePuddles += 1
+    if (oldestActivePuddleIndex < 0) oldestActivePuddleIndex = index
+  }
+  if (activePuddles <= MAX_FIRE_PUDDLES || oldestActivePuddleIndex < 0) return hazards
+
+  return hazards.map((hazard, index) => index === oldestActivePuddleIndex
+    ? { ...hazard, remainingSeconds: Math.min(hazard.remainingSeconds, hazard.fadeSeconds) }
+    : hazard)
+}

src/modes/iwt2/sim/healing.ts

@@ -0,0 +1,124 @@
+import type { Iwt2HealerAbility } from '../content/healerAbilities'
+import type {
+  Iwt2ArenaEvent,
+  Iwt2ArenaState,
+  Iwt2EntityId,
+  Iwt2PartyEntityState,
+} from './types'
+import { createArenaEvent } from './mechanics'
+
+const HEALER_ID: Iwt2EntityId = 'player-healer'
+const MAX_EVENTS = 80
+const DEFAULT_HOT_SECONDS = 8
+const DEFAULT_HOT_TICK_SECONDS = 1
+
+export type Iwt2HealerCastResult<TState extends Iwt2ArenaState = Iwt2ArenaState> = {
+  cast: boolean
+  state: TState
+}
+
+export function castIwt2HealerAbility<TState extends Iwt2ArenaState>(
+  state: TState,
+  ability: Iwt2HealerAbility,
+  selectedTargetId: Iwt2EntityId,
+): Iwt2HealerCastResult<TState> {
+  if (state.boss.health <= 0) return { cast: false, state }
+  const healer = state.party.find((member) => member.id === HEALER_ID)
+  if (!healer || healer.health <= 0 || healer.mana < ability.manaCost) return { cast: false, state }
+
+  const targetIds = targetIdsForAbility(state.party, ability, selectedTargetId)
+  if (targetIds.length === 0) return { cast: false, state }
+
+  const events: Iwt2ArenaEvent[] = []
+  let eventId = state.nextEventId
+  const targetIdSet = new Set(targetIds)
+  const nextParty = state.party.map((member) => {
+    const mana = member.id === HEALER_ID ? Math.max(0, member.mana - ability.manaCost) : member.mana
+    if (!targetIdSet.has(member.id)) return { ...member, mana }
+
+    const nextMember = applyAbilityToMember(member, ability)
+    const healed = Math.max(0, nextMember.health - member.health)
+    if (healed > 0) {
+      events.push(createArenaEvent(eventId, state.time, 'partyHealed', HEALER_ID, member.id, healed))
+      eventId += 1
+    }
+    return { ...nextMember, mana }
+  })
+
+  return {
+    cast: true,
+    state: {
+      ...state,
+      party: nextParty,
+      nextEventId: eventId,
+      events: [...state.events, ...events].slice(-MAX_EVENTS),
+    } as TState,
+  }
+}
+
+function targetIdsForAbility(
+  party: Iwt2PartyEntityState[],
+  ability: Iwt2HealerAbility,
+  selectedTargetId: Iwt2EntityId,
+): Iwt2EntityId[] {
+  const living = party.filter((member) => member.health > 0)
+  if (living.length === 0) return []
+  if (ability.kind === 'group') {
+    return [...living]
+      .sort((a, b) => healthRatio(a) - healthRatio(b))
+      .slice(0, 4)
+      .map((member) => member.id)
+  }
+  const selected = living.find((member) => member.id === selectedTargetId)
+  return [selected?.id ?? living[0].id]
+}
+
+function applyAbilityToMember(member: Iwt2PartyEntityState, ability: Iwt2HealerAbility): Iwt2PartyEntityState {
+  if (ability.kind === 'hot') {
+    return {
+      ...healMember(member, ability.power),
+      hotEffects: [
+        ...member.hotEffects.filter((effect) => effect.id !== ability.id),
+        {
+          id: ability.id,
+          label: ability.name,
+          power: Math.max(1, Math.round(ability.power * 0.5)),
+          remainingSeconds: DEFAULT_HOT_SECONDS,
+          tickIntervalSeconds: DEFAULT_HOT_TICK_SECONDS,
+          nextTickInSeconds: DEFAULT_HOT_TICK_SECONDS,
+        },
+      ],
+    }
+  }
+
+  if (ability.kind === 'shield') {
+    return {
+      ...member,
+      shield: Math.max(member.shield, ability.power),
+    }
+  }
+
+  if (ability.kind === 'cleanse') {
+    return {
+      ...healMember(member, ability.power),
+      status: {
+        ...member.status,
+        knockedDownSeconds: 0,
+        stunnedSeconds: 0,
+      },
+    }
+  }
+
+  return healMember(member, ability.power)
+}
+
+function healMember(member: Iwt2PartyEntityState, amount: number): Iwt2PartyEntityState {
+  return {
+    ...member,
+    health: Math.min(member.maxHealth, member.health + amount),
+  }
+}
+
+function healthRatio(member: Iwt2PartyEntityState) {
+  return member.health / member.maxHealth
+}

src/modes/iwt2/sim/index.ts

@@ -0,0 +1,67 @@
+export {
+  createInitialIwt2ArenaState,
+  tickIwt2Arena,
+} from './arena'
+
+export {
+  circlesOverlap,
+  circleIntersectsSegment,
+  distanceToSegment,
+  separateCircles,
+} from './collision'
+
+export {
+  applyPartyDamageInShape,
+  createArenaEvent,
+  createCircleIndicator,
+  createConeIndicator,
+  createDonutIndicator,
+  createLaneIndicator,
+  createLinearMovementPlan,
+  indicatorPhaseFromAttack,
+  isIndicatorActive,
+  partyMemberIntersectsShape,
+} from './mechanics'
+
+export {
+  castIwt2HealerAbility,
+} from './healing'
+
+export {
+  addVec2,
+  clamp,
+  clampVec2ToArena,
+  distanceVec2,
+  dotVec2,
+  lengthSqVec2,
+  lengthVec2,
+  moveToward,
+  normalizeVec2,
+  scaleVec2,
+  subtractVec2,
+} from './vector'
+
+export type {
+  Iwt2ArenaBounds,
+  Iwt2ArenaEvent,
+  Iwt2ArenaEventType,
+  Iwt2ArenaIndicator,
+  Iwt2ArenaIndicatorPhase,
+  Iwt2ArenaInput,
+  Iwt2ArenaState,
+  Iwt2BossAttackPhase,
+  Iwt2BossEntityState,
+  Iwt2Circle,
+  Iwt2EntityId,
+  Iwt2EntityKind,
+  Iwt2GroundHazardState,
+  Iwt2HotEffectState,
+  Iwt2HostileAddAttackPhase,
+  Iwt2HostileAddState,
+  Iwt2PartyAiRole,
+  Iwt2PartyEntityId,
+  Iwt2PartyEntityState,
+  Iwt2ProjectileEntityState,
+  Iwt2StatusState,
+  Iwt2Vec2,
+} from './types'

src/modes/iwt2/sim/mechanics.ts

@@ -0,0 +1,308 @@
+import type {
+  Iwt2ArenaBounds,
+  Iwt2ArenaCircleIndicator,
+  Iwt2ArenaConeIndicator,
+  Iwt2ArenaDonutIndicator,
+  Iwt2ArenaEvent,
+  Iwt2ArenaEventType,
+  Iwt2ArenaIndicator,
+  Iwt2ArenaIndicatorPhase,
+  Iwt2ArenaLaneIndicator,
+  Iwt2EntityId,
+  Iwt2PartyEntityState,
+  Iwt2Vec2,
+} from './types'
+import { circleIntersectsSegment } from './collision'
+import {
+  addVec2,
+  clampVec2ToArena,
+  distanceVec2,
+  normalizeVec2,
+  scaleVec2,
+  subtractVec2,
+} from './vector'
+
+export type Iwt2LinearMovementPlan = {
+  direction: Iwt2Vec2
+  end: Iwt2Vec2
+}
+
+export type Iwt2PartyDamageEffect = {
+  sourceId: Iwt2EntityId
+  time: number
+  damage: number
+  damageEventType?: Iwt2ArenaEventType
+  stunSeconds?: number
+  knockdownSeconds?: number
+  statusEventType?: Iwt2ArenaEventType
+  excludedEntityIds?: Iwt2EntityId[]
+}
+
+export type Iwt2LaneHitShape = {
+  kind: 'lane'
+  start: Iwt2Vec2
+  end: Iwt2Vec2
+  width: number
+}
+
+export type Iwt2CircleHitShape = {
+  kind: 'circle'
+  position: Iwt2Vec2
+  radius: number
+}
+
+export type Iwt2HitShape = Iwt2LaneHitShape | Iwt2CircleHitShape
+
+export function createArenaEvent(
+  id: number,
+  time: number,
+  type: Iwt2ArenaEventType,
+  sourceId: Iwt2EntityId,
+  targetId?: Iwt2EntityId,
+  value?: number,
+): Iwt2ArenaEvent {
+  return { id, time, type, sourceId, targetId, value }
+}
+
+export function createLinearMovementPlan({
+  bounds,
+  from,
+  length,
+  radius,
+  target,
+}: {
+  bounds: Iwt2ArenaBounds
+  from: Iwt2Vec2
+  length: number
+  radius: number
+  target: Iwt2Vec2
+}): Iwt2LinearMovementPlan {
+  const direction = normalizeVec2(subtractVec2(target, from))
+  const rawEnd = addVec2(from, scaleVec2(direction, length))
+  return {
+    direction,
+    end: clampVec2ToArena(rawEnd, radius, bounds),
+  }
+}
+
+export function applyPartyDamageInShape(
+  party: Iwt2PartyEntityState[],
+  shape: Iwt2HitShape,
+  effect: Iwt2PartyDamageEffect,
+): {
+  party: Iwt2PartyEntityState[]
+  hitEntityIds: Iwt2EntityId[]
+  events: Iwt2ArenaEvent[]
+} {
+  const events: Iwt2ArenaEvent[] = []
+  const excluded = new Set(effect.excludedEntityIds ?? [])
+  const hitEntityIds: Iwt2EntityId[] = []
+  const stunSeconds = effect.stunSeconds ?? 0
+  const knockdownSeconds = effect.knockdownSeconds ?? stunSeconds
+  const nextParty = party.map((member) => {
+    if (member.health <= 0 || excluded.has(member.id) || !partyMemberIntersectsShape(member, shape)) {
+      return member
+    }
+
+    hitEntityIds.push(member.id)
+    const shieldAbsorbed = Math.min(member.shield, effect.damage)
+    const healthDamage = effect.damage - shieldAbsorbed
+    const nextShield = member.shield - shieldAbsorbed
+    const nextHealth = Math.max(0, member.health - healthDamage)
+    events.push(createArenaEvent(
+      0,
+      effect.time,
+      effect.damageEventType ?? 'partyDamaged',
+      effect.sourceId,
+      member.id,
+      effect.damage,
+    ))
+    if (stunSeconds > 0 || knockdownSeconds > 0) {
+      events.push(createArenaEvent(
+        0,
+        effect.time,
+        effect.statusEventType ?? 'partyStunned',
+        effect.sourceId,
+        member.id,
+        Math.max(stunSeconds, knockdownSeconds),
+      ))
+    }
+    if (member.health > 0 && nextHealth <= 0) {
+      events.push(createArenaEvent(0, effect.time, 'entityDefeated', effect.sourceId, member.id))
+    }
+
+    return {
+      ...member,
+      health: nextHealth,
+      shield: nextShield,
+      status: {
+        ...member.status,
+        stunnedSeconds: Math.max(member.status.stunnedSeconds, stunSeconds),
+        knockedDownSeconds: Math.max(member.status.knockedDownSeconds, knockdownSeconds),
+      },
+    }
+  })
+
+  return { party: nextParty, hitEntityIds, events }
+}
+
+export function partyMemberIntersectsShape(member: Iwt2PartyEntityState, shape: Iwt2HitShape): boolean {
+  if (shape.kind === 'lane') {
+    return circleIntersectsSegment(
+      { position: member.position, radius: member.radius },
+      shape.start,
+      shape.end,
+      shape.width,
+    )
+  }
+  return distanceVec2(member.position, shape.position) <= shape.radius + member.radius
+}
+
+export function createLaneIndicator({
+  color,
+  end,
+  id,
+  mechanicId,
+  phase,
+  sourceId,
+  start,
+  width,
+}: {
+  color: string
+  end: Iwt2Vec2
+  id: string
+  mechanicId: string
+  phase: Iwt2ArenaIndicatorPhase
+  sourceId: Iwt2EntityId
+  start: Iwt2Vec2
+  width: number
+}): Iwt2ArenaLaneIndicator {
+  return {
+    color,
+    end: { ...end },
+    fillAlpha: phase === 'active' ? 0.18 : 0.11,
+    id,
+    kind: 'lane',
+    lineAlpha: phase === 'active' ? 0.8 : 0.45,
+    mechanicId,
+    phase,
+    sourceId,
+    start: { ...start },
+    width,
+  }
+}
+
+export function createCircleIndicator({
+  color,
+  id,
+  mechanicId,
+  phase,
+  position,
+  radius,
+  sourceId,
+}: {
+  color: string
+  id: string
+  mechanicId: string
+  phase: Iwt2ArenaIndicatorPhase
+  position: Iwt2Vec2
+  radius: number
+  sourceId: Iwt2EntityId
+}): Iwt2ArenaCircleIndicator {
+  return {
+    color,
+    fillAlpha: phase === 'active' ? 0.18 : 0.12,
+    id,
+    kind: 'circle',
+    lineAlpha: phase === 'active' ? 0.75 : 0.55,
+    mechanicId,
+    phase,
+    position: { ...position },
+    radius,
+    sourceId,
+  }
+}
+
+export function createConeIndicator({
+  angleRadians,
+  color,
+  direction,
+  id,
+  mechanicId,
+  origin,
+  phase,
+  range,
+  sourceId,
+}: {
+  angleRadians: number
+  color: string
+  direction: Iwt2Vec2
+  id: string
+  mechanicId: string
+  origin: Iwt2Vec2
+  phase: Iwt2ArenaIndicatorPhase
+  range: number
+  sourceId: Iwt2EntityId
+}): Iwt2ArenaConeIndicator {
+  return {
+    angleRadians,
+    color,
+    direction: normalizeVec2(direction),
+    fillAlpha: phase === 'active' ? 0.18 : 0.1,
+    id,
+    kind: 'cone',
+    lineAlpha: phase === 'active' ? 0.72 : 0.48,
+    mechanicId,
+    origin: { ...origin },
+    phase,
+    range,
+    sourceId,
+  }
+}
+
+export function createDonutIndicator({
+  color,
+  id,
+  innerRadius,
+  mechanicId,
+  outerRadius,
+  phase,
+  position,
+  sourceId,
+}: {
+  color: string
+  id: string
+  innerRadius: number
+  mechanicId: string
+  outerRadius: number
+  phase: Iwt2ArenaIndicatorPhase
+  position: Iwt2Vec2
+  sourceId: Iwt2EntityId
+}): Iwt2ArenaDonutIndicator {
+  return {
+    color,
+    fillAlpha: phase === 'active' ? 0.14 : 0.08,
+    id,
+    innerRadius,
+    kind: 'donut',
+    lineAlpha: phase === 'active' ? 0.76 : 0.5,
+    mechanicId,
+    outerRadius,
+    phase,
+    position: { ...position },
+    sourceId,
+  }
+}
+
+export function indicatorPhaseFromAttack(
+  windup: boolean,
+  active: boolean,
+): Iwt2ArenaIndicatorPhase {
+  if (active) return 'active'
+  if (windup) return 'windup'
+  return 'recover'
+}
+
+export function isIndicatorActive(indicator: Iwt2ArenaIndicator): boolean {
+  return indicator.phase === 'active'
+}

src/modes/iwt2/sim/partyAi.ts

@@ -0,0 +1,230 @@
+import { IWT2_CLASS_METADATA } from '../content/classes'
+import { BULLDROME_BOSS_METADATA } from '../content/bosses'
+import type { Iwt2ArenaState, Iwt2HostileAddState, Iwt2PartyEntityState, Iwt2Vec2 } from './types'
+import {
+  addVec2,
+  clampVec2ToArena,
+  distanceVec2,
+  dotVec2,
+  lengthSqVec2,
+  moveToward,
+  normalizeVec2,
+  scaleVec2,
+  subtractVec2,
+  withFallbackFacing,
+} from './vector'
+
+export function tickPartyMember(
+  member: Iwt2PartyEntityState,
+  state: Iwt2ArenaState,
+  inputMove: Iwt2Vec2,
+  dt: number,
+): Iwt2PartyEntityState {
+  const metadata = IWT2_CLASS_METADATA[member.classId]
+  const status = {
+    stunnedSeconds: Math.max(0, member.status.stunnedSeconds - dt),
+    knockedDownSeconds: Math.max(0, member.status.knockedDownSeconds - dt),
+    invulnerableSeconds: Math.max(0, member.status.invulnerableSeconds - dt),
+  }
+  const attackCooldownRemaining = Math.max(0, member.attackCooldownRemaining - dt)
+  const castSecondsRemaining = Math.max(0, member.castSecondsRemaining - dt)
+  if (member.health <= 0) {
+    return { ...member, velocity: { x: 0, y: 0 }, attackCooldownRemaining, castSecondsRemaining: 0, attackReady: false, status }
+  }
+  if (status.stunnedSeconds > 0 || status.knockedDownSeconds > 0) {
+    return { ...member, velocity: { x: 0, y: 0 }, attackCooldownRemaining, castSecondsRemaining: 0, attackReady: false, status }
+  }
+
+  if (member.aiRole === 'player') {
+    const normalizedInput = lengthSqVec2(inputMove) > 1 ? normalizeVec2(inputMove) : inputMove
+    const velocity = scaleVec2(normalizedInput, metadata.moveSpeed)
+    const position = clampVec2ToArena(
+      {
+        x: member.position.x + velocity.x * dt,
+        y: member.position.y + velocity.y * dt,
+      },
+      member.radius,
+      state.bounds,
+    )
+    return {
+      ...member,
+      position,
+      velocity,
+      facing: withFallbackFacing(velocity, member.facing),
+      attackCooldownRemaining,
+      castSecondsRemaining: 0,
+      attackReady: false,
+      status,
+    }
+  }
+
+  const dangerDestination = getDangerAvoidancePosition(member, state)
+  const attackTarget = getPriorityAttackTarget(member, state)
+  const canCast = member.aiRole === 'ranged'
+    && attackCooldownRemaining <= 0
+    && !!attackTarget
+    && canPartyMemberHitTarget({ ...member, attackCooldownRemaining, castSecondsRemaining }, attackTarget.position)
+  if (!dangerDestination && member.aiRole === 'ranged' && (member.castSecondsRemaining > 0 || canCast)) {
+    const nextCastSecondsRemaining = member.castSecondsRemaining > 0
+      ? castSecondsRemaining
+      : metadata.castTime
+    return {
+      ...member,
+      velocity: { x: 0, y: 0 },
+      facing: withFallbackFacing(subtractVec2(attackTarget?.position ?? state.boss.position, member.position), member.facing),
+      attackCooldownRemaining,
+      castSecondsRemaining: nextCastSecondsRemaining,
+      attackReady: member.castSecondsRemaining > 0 && nextCastSecondsRemaining <= 0,
+      status,
+    }
+  }
+
+  const decisionSecondsRemaining = Math.max(0, member.decisionSecondsRemaining - dt)
+  const desired = dangerDestination ?? getPartyDesiredPosition(member, state, decisionSecondsRemaining)
+  const maxDistance = metadata.moveSpeed * dt
+  const position = clampVec2ToArena(moveToward(member.position, desired, maxDistance), member.radius, state.bounds)
+  const velocity = scaleVec2(subtractVec2(position, member.position), dt > 0 ? 1 / dt : 0)
+  return {
+    ...member,
+    position,
+    velocity,
+    facing: withFallbackFacing(subtractVec2(attackTarget?.position ?? state.boss.position, position), member.facing),
+    attackCooldownRemaining,
+    castSecondsRemaining: 0,
+    attackReady: false,
+    status,
+    decisionSecondsRemaining: decisionSecondsRemaining <= 0
+      ? nextDecisionInterval(member)
+      : decisionSecondsRemaining,
+  }
+}
+
+export function canPartyMemberHitTarget(member: Iwt2PartyEntityState, targetPosition: Iwt2Vec2): boolean {
+  if (member.health <= 0) return false
+  if (member.status.stunnedSeconds > 0 || member.status.knockedDownSeconds > 0) return false
+  const metadata = IWT2_CLASS_METADATA[member.classId]
+  if (metadata.attackDamage <= 0) return false
+  return distanceVec2(member.position, targetPosition) <= metadata.attackRange + member.radius
+}
+
+function getPartyDesiredPosition(
+  member: Iwt2PartyEntityState,
+  state: Iwt2ArenaState,
+  decisionSecondsRemaining: number,
+): Iwt2Vec2 {
+  const drift = decisionSecondsRemaining <= 0 ? decisionDrift(member, state.time) : { x: 0, y: 0 }
+  const attackTarget = getPriorityAttackTarget(member, state)
+  const anchor = attackTarget?.position ?? state.boss.position
+  return {
+    x: anchor.x + member.preferredOffset.x + drift.x,
+    y: anchor.y + member.preferredOffset.y + drift.y,
+  }
+}
+
+function getDangerAvoidancePosition(member: Iwt2PartyEntityState, state: Iwt2ArenaState): Iwt2Vec2 | null {
+  const boss = state.boss
+  const hazardEscape = getHazardAvoidancePosition(member, state)
+  if (hazardEscape) {
+    return hazardEscape
+  }
+
+  if (boss.bossId === 'bulldrome' && (boss.attackPhase === 'slamWindup' || boss.attackPhase === 'slamRecover')) {
+    const distance = distanceVec2(member.position, boss.position)
+    const dangerRadius = BULLDROME_BOSS_METADATA.slamRadius + member.radius + 34
+    if (distance < dangerRadius) {
+      const away = normalizeVec2(subtractVec2(member.position, boss.position))
+      return clampVec2ToArena(addVec2(member.position, scaleVec2(away, dangerRadius - distance + 40)), member.radius, state.bounds)
+    }
+  }
+
+  if (boss.bossId === 'bulldrome' && (boss.attackPhase === 'chargeWindup' || boss.attackPhase === 'charging')) {
+    const danger = chargeDanger(member.position, state)
+    if (danger.inside || danger.ahead) {
+      const perpendicular = { x: -danger.direction.y, y: danger.direction.x }
+      const side = dotVec2(subtractVec2(member.position, boss.chargeStart), perpendicular) >= 0 ? 1 : -1
+      const escape = addVec2(member.position, scaleVec2(perpendicular, side * (boss.radius * 2.8 + member.radius)))
+      return clampVec2ToArena(escape, member.radius, state.bounds)
+    }
+  }
+
+  return null
+}
+
+function getHazardAvoidancePosition(member: Iwt2PartyEntityState, state: Iwt2ArenaState): Iwt2Vec2 | null {
+  let escape = { x: 0, y: 0 }
+  let maxNeededDistance = 0
+
+  for (const hazard of state.hazards) {
+    const offset = subtractVec2(member.position, hazard.position)
+    const distance = distanceVec2(member.position, hazard.position)
+    const dangerRadius = hazard.radius + member.radius + 46
+    if (distance >= dangerRadius) continue
+
+    const fallback = withFallbackFacing(subtractVec2(member.position, state.boss.position), {
+      x: member.position.x < state.bounds.width * 0.5 ? -1 : 1,
+      y: member.position.y < state.bounds.height * 0.5 ? -0.35 : 0.35,
+    })
+    const away = distance > 0.001 ? normalizeVec2(offset) : fallback
+    const urgency = dangerRadius - distance
+    escape = addVec2(escape, scaleVec2(away, urgency))
+    maxNeededDistance = Math.max(maxNeededDistance, urgency)
+  }
+
+  if (maxNeededDistance <= 0) return null
+
+  const direction = withFallbackFacing(escape, {
+    x: member.position.x < state.bounds.width * 0.5 ? -1 : 1,
+    y: 0,
+  })
+  return clampVec2ToArena(
+    addVec2(member.position, scaleVec2(direction, maxNeededDistance + 72)),
+    member.radius,
+    state.bounds,
+  )
+}
+
+function getPriorityAttackTarget(
+  member: Iwt2PartyEntityState,
+  state: Iwt2ArenaState,
+): (Iwt2ArenaState['boss'] | Iwt2HostileAddState) | undefined {
+  if (member.health <= 0) return undefined
+  const livingAdds = state.hostileAdds.filter((add) => add.health > 0)
+  if (livingAdds.length > 0) {
+    return livingAdds.reduce((best, add) => (
+      distanceVec2(member.position, add.position) < distanceVec2(member.position, best.position) ? add : best
+    ), livingAdds[0])
+  }
+  return state.boss.health > 0 ? state.boss : undefined
+}
+
+function chargeDanger(position: Iwt2Vec2, state: Iwt2ArenaState) {
+  const boss = state.boss
+  const segment = subtractVec2(boss.chargeEnd, boss.chargeStart)
+  const lengthSq = Math.max(1, lengthSqVec2(segment))
+  const direction = normalizeVec2(segment)
+  const offset = subtractVec2(position, boss.chargeStart)
+  const along = dotVec2(offset, segment) / lengthSq
+  const closest = addVec2(boss.chargeStart, scaleVec2(segment, Math.min(1, Math.max(0, along))))
+  const distance = distanceVec2(position, closest)
+  const width = boss.radius + 22
+  return {
+    direction,
+    inside: along >= -0.08 && along <= 1.08 && distance <= width,
+    ahead: boss.attackPhase === 'chargeWindup' && along > -0.12 && along < 1.05 && distance <= width + 38,
+  }
+}
+
+function decisionDrift(member: Iwt2PartyEntityState, time: number): Iwt2Vec2 {
+  const seed = member.id.length * 17
+  return {
+    x: Math.sin(time * 0.7 + seed) * 16,
+    y: Math.cos(time * 0.9 + seed) * 14,
+  }
+}
+
+function nextDecisionInterval(member: Iwt2PartyEntityState): number {
+  if (member.aiRole === 'tank') return 0.34
+  if (member.aiRole === 'ranged') return 0.48
+  if (member.aiRole === 'flanker') return 0.28
+  return 0.38
+}

src/modes/iwt2/sim/types.ts

@@ -0,0 +1,254 @@
+import type { Iwt2BossId } from '../content/bosses'
+import type { Iwt2PlayerClassId } from '../content/classes'
+
+export type Iwt2Vec2 = {
+  x: number
+  y: number
+}
+
+export type Iwt2ArenaBounds = {
+  width: number
+  height: number
+}
+
+export type Iwt2PartyEntityId =
+  | 'player-healer'
+  | 'paladin-tank'
+  | 'ranger'
+  | 'mage'
+  | 'rogue'
+  | 'warrior'
+
+export type Iwt2BossEntityId = Iwt2BossId
+
+export type Iwt2EntityId = Iwt2PartyEntityId | Iwt2BossEntityId | string
+
+export type Iwt2EntityKind = 'party' | 'boss' | 'hostileAdd'
+
+export type Iwt2PartyAiRole = 'player' | 'tank' | 'ranged' | 'flanker' | 'melee'
+
+export type Iwt2StatusState = {
+  stunnedSeconds: number
+  knockedDownSeconds: number
+  invulnerableSeconds: number
+}
+
+export type Iwt2HotEffectState = {
+  id: string
+  label: string
+  power: number
+  remainingSeconds: number
+  tickIntervalSeconds: number
+  nextTickInSeconds: number
+}
+
+export type Iwt2PartyEntityState = {
+  id: Iwt2PartyEntityId
+  kind: 'party'
+  classId: Iwt2PlayerClassId
+  aiRole: Iwt2PartyAiRole
+  position: Iwt2Vec2
+  velocity: Iwt2Vec2
+  facing: Iwt2Vec2
+  radius: number
+  health: number
+  maxHealth: number
+  shield: number
+  mana: number
+  maxMana: number
+  damageDone: number
+  attackCooldownRemaining: number
+  castSecondsRemaining: number
+  attackReady: boolean
+  status: Iwt2StatusState
+  hotEffects: Iwt2HotEffectState[]
+  preferredOffset: Iwt2Vec2
+  decisionSecondsRemaining: number
+}
+
+export type Iwt2ProjectileEntityState = {
+  id: string
+  sourceId: Iwt2EntityId
+  owner: 'party' | 'boss'
+  classId?: Iwt2PlayerClassId
+  projectileKind: 'arrow' | 'fireball' | 'magic'
+  color: string
+  position: Iwt2Vec2
+  velocity: Iwt2Vec2
+  radius: number
+  damage: number
+  remainingSeconds: number
+  bouncesRemaining?: number
+  bounceCooldownSeconds?: number
+}
+
+export type Iwt2BossAttackPhase =
+  | 'idle'
+  | 'chargeWindup'
+  | 'charging'
+  | 'chargeRecover'
+  | 'slamWindup'
+  | 'slamRecover'
+  | 'relocating'
+  | 'fireballWindup'
+  | 'fireballRecover'
+  | 'birdSummonWindup'
+  | 'birdSummonRecover'
+
+export type Iwt2HostileAddAttackPhase =
+  | 'idle'
+  | 'flightWindup'
+  | 'flying'
+  | 'flightRecover'
+
+export type Iwt2BossEntityState = {
+  id: Iwt2BossEntityId
+  kind: 'boss'
+  bossId: Iwt2BossId
+  position: Iwt2Vec2
+  velocity: Iwt2Vec2
+  facing: Iwt2Vec2
+  radius: number
+  health: number
+  maxHealth: number
+  meleeCooldownRemaining: number
+  chargeCooldownRemaining: number
+  chargeCount: number
+  attackPhase: Iwt2BossAttackPhase
+  phaseSecondsRemaining: number
+  chargeStart: Iwt2Vec2
+  chargeEnd: Iwt2Vec2
+  chargeHitEntityIds: Iwt2EntityId[]
+  slamApplied: boolean
+  wallContactSeconds: number
+  relocateTarget: Iwt2Vec2
+  fireballCooldownRemaining: number
+  fireballTarget: Iwt2Vec2
+  birdWaveThresholdsTriggered: number[]
+}
+
+export type Iwt2HostileAddState = {
+  id: string
+  kind: 'hostileAdd'
+  addKind: 'yian-bird'
+  sourceBossId: Iwt2BossId
+  position: Iwt2Vec2
+  velocity: Iwt2Vec2
+  facing: Iwt2Vec2
+  radius: number
+  health: number
+  maxHealth: number
+  damageDone: number
+  attackCooldownRemaining: number
+  flightCooldownRemaining: number
+  attackPhase: Iwt2HostileAddAttackPhase
+  phaseSecondsRemaining: number
+  flightStart: Iwt2Vec2
+  flightEnd: Iwt2Vec2
+  flightHitEntityIds: Iwt2EntityId[]
+}
+
+export type Iwt2GroundHazardState = {
+  id: string
+  kind: 'groundHazard'
+  hazardKind: 'firePuddle'
+  sourceId: Iwt2EntityId
+  position: Iwt2Vec2
+  radius: number
+  damage: number
+  remainingSeconds: number
+  fadeSeconds: number
+  nextDamageAt: number
+}
+
+export type Iwt2ArenaEventType =
+  | 'bossDamaged'
+  | 'partyHealed'
+  | 'partyDamaged'
+  | 'partyStunned'
+  | 'bossChargeStart'
+  | 'bossChargeHit'
+  | 'bossSlam'
+  | 'entityDefeated'
+
+export type Iwt2ArenaEvent = {
+  id: number
+  time: number
+  type: Iwt2ArenaEventType
+  sourceId: Iwt2EntityId
+  targetId?: Iwt2EntityId
+  value?: number
+}
+
+export type Iwt2ArenaIndicatorPhase = 'windup' | 'active' | 'recover'
+
+export type Iwt2ArenaIndicatorBase = {
+  id: string
+  mechanicId: string
+  sourceId: Iwt2EntityId
+  phase: Iwt2ArenaIndicatorPhase
+  color: string
+  fillAlpha?: number
+  lineAlpha?: number
+}
+
+export type Iwt2ArenaLaneIndicator = Iwt2ArenaIndicatorBase & {
+  kind: 'lane'
+  start: Iwt2Vec2
+  end: Iwt2Vec2
+  width: number
+}
+
+export type Iwt2ArenaCircleIndicator = Iwt2ArenaIndicatorBase & {
+  kind: 'circle'
+  position: Iwt2Vec2
+  radius: number
+}
+
+export type Iwt2ArenaConeIndicator = Iwt2ArenaIndicatorBase & {
+  kind: 'cone'
+  origin: Iwt2Vec2
+  direction: Iwt2Vec2
+  range: number
+  angleRadians: number
+}
+
+export type Iwt2ArenaDonutIndicator = Iwt2ArenaIndicatorBase & {
+  kind: 'donut'
+  position: Iwt2Vec2
+  innerRadius: number
+  outerRadius: number
+}
+
+export type Iwt2ArenaIndicator =
+  | Iwt2ArenaLaneIndicator
+  | Iwt2ArenaCircleIndicator
+  | Iwt2ArenaConeIndicator
+  | Iwt2ArenaDonutIndicator
+
+export type Iwt2ArenaState = {
+  schemaVersion: 1
+  time: number
+  bounds: Iwt2ArenaBounds
+  party: Iwt2PartyEntityState[]
+  projectiles: Iwt2ProjectileEntityState[]
+  hostileAdds: Iwt2HostileAddState[]
+  hazards: Iwt2GroundHazardState[]
+  boss: Iwt2BossEntityState
+  indicators: Iwt2ArenaIndicator[]
+  nextEventId: number
+  nextProjectileId: number
+  nextAddId: number
+  nextHazardId: number
+  events: Iwt2ArenaEvent[]
+}
+
+export type Iwt2ArenaInput = {
+  moveX: number
+  moveY: number
+}
+
+export type Iwt2Circle = {
+  position: Iwt2Vec2
+  radius: number
+}

src/modes/iwt2/sim/vector.ts

@@ -0,0 +1,60 @@
+import type { Iwt2ArenaBounds, Iwt2Vec2 } from './types'
+
+export const IWT2_ZERO_VECTOR: Iwt2Vec2 = { x: 0, y: 0 }
+
+export function addVec2(a: Iwt2Vec2, b: Iwt2Vec2): Iwt2Vec2 {
+  return { x: a.x + b.x, y: a.y + b.y }
+}
+
+export function subtractVec2(a: Iwt2Vec2, b: Iwt2Vec2): Iwt2Vec2 {
+  return { x: a.x - b.x, y: a.y - b.y }
+}
+
+export function scaleVec2(vector: Iwt2Vec2, scale: number): Iwt2Vec2 {
+  return { x: vector.x * scale, y: vector.y * scale }
+}
+
+export function dotVec2(a: Iwt2Vec2, b: Iwt2Vec2): number {
+  return a.x * b.x + a.y * b.y
+}
+
+export function lengthSqVec2(vector: Iwt2Vec2): number {
+  return dotVec2(vector, vector)
+}
+
+export function lengthVec2(vector: Iwt2Vec2): number {
+  return Math.sqrt(lengthSqVec2(vector))
+}
+
+export function distanceVec2(a: Iwt2Vec2, b: Iwt2Vec2): number {
+  return lengthVec2(subtractVec2(a, b))
+}
+
+export function normalizeVec2(vector: Iwt2Vec2): Iwt2Vec2 {
+  const length = lengthVec2(vector)
+  if (length <= 0.0001) return { ...IWT2_ZERO_VECTOR }
+  return { x: vector.x / length, y: vector.y / length }
+}
+
+export function clamp(value: number, min: number, max: number): number {
+  return Math.min(max, Math.max(min, value))
+}
+
+export function clampVec2ToArena(position: Iwt2Vec2, radius: number, bounds: Iwt2ArenaBounds): Iwt2Vec2 {
+  return {
+    x: clamp(position.x, radius, bounds.width - radius),
+    y: clamp(position.y, radius, bounds.height - radius),
+  }
+}
+
+export function moveToward(current: Iwt2Vec2, target: Iwt2Vec2, maxDistance: number): Iwt2Vec2 {
+  const offset = subtractVec2(target, current)
+  const distance = lengthVec2(offset)
+  if (distance <= maxDistance || distance <= 0.0001) return { ...target }
+  return addVec2(current, scaleVec2(offset, maxDistance / distance))
+}
+
+export function withFallbackFacing(nextFacing: Iwt2Vec2, fallback: Iwt2Vec2): Iwt2Vec2 {
+  if (lengthSqVec2(nextFacing) <= 0.0001) return { ...fallback }
+  return normalizeVec2(nextFacing)
+}

src/modes/iwt2/sim/yianKutKuAi.ts

@@ -0,0 +1,707 @@
+import { YIAN_KUT_KU_BOSS_METADATA, type Iwt2BossId } from '../content/bosses'
+import type {
+  Iwt2ArenaEvent,
+  Iwt2ArenaIndicator,
+  Iwt2ArenaState,
+  Iwt2BossEntityState,
+  Iwt2GroundHazardState,
+  Iwt2HostileAddState,
+  Iwt2PartyEntityState,
+  Iwt2ProjectileEntityState,
+  Iwt2Vec2,
+} from './types'
+import {
+  applyPartyDamageInShape,
+  createCircleIndicator,
+  createLaneIndicator,
+  indicatorPhaseFromAttack,
+  partyMemberIntersectsShape,
+} from './mechanics'
+import { addFirePuddle } from './hazards'
+import {
+  clamp,
+  clampVec2ToArena,
+  distanceVec2,
+  moveToward,
+  normalizeVec2,
+  scaleVec2,
+  subtractVec2,
+  withFallbackFacing,
+} from './vector'
+
+export type Iwt2YianTickResult = {
+  boss: Iwt2BossEntityState
+  party: Iwt2PartyEntityState[]
+  hostileAdds: Iwt2HostileAddState[]
+  hazards: Iwt2GroundHazardState[]
+  projectiles: Iwt2ProjectileEntityState[]
+  events: Iwt2ArenaEvent[]
+  indicators: Iwt2ArenaIndicator[]
+  nextAddId: number
+  nextHazardId: number
+  nextProjectileId: number
+}
+
+const BIRD_COUNT = 3
+const BIRD_MELEE_RANGE = 24
+const BIRD_MELEE_COOLDOWN = 1.15
+const BIRD_FLIGHT_DAMAGE = 10
+const YIAN_FIREBALL_BOUNCES = 8
+const YIAN_SAFE_WALL_MARGIN = 118
+const YIAN_CENTER_CAST_DISTANCE = 36
+const YIAN_CENTER_CHARGE_SPEED = 430
+
+export function tickYianKutKu(state: Iwt2ArenaState, dt: number): Iwt2YianTickResult {
+  const events: Iwt2ArenaEvent[] = []
+  const projectiles: Iwt2ProjectileEntityState[] = []
+  let party = state.party
+  let hazards = state.hazards
+  let nextAddId = state.nextAddId
+  let nextHazardId = state.nextHazardId
+  let nextProjectileId = state.nextProjectileId
+  let boss = {
+    ...state.boss,
+    meleeCooldownRemaining: Math.max(0, state.boss.meleeCooldownRemaining - dt),
+    fireballCooldownRemaining: Math.max(0, state.boss.fireballCooldownRemaining - dt),
+    phaseSecondsRemaining: Math.max(0, state.boss.phaseSecondsRemaining - dt),
+    velocity: { x: 0, y: 0 },
+  }
+
+  const birdResult = tickYianBirds({
+    dt,
+    hazards,
+    nextHazardId,
+    party,
+    state,
+    time: state.time + dt,
+  })
+  party = birdResult.party
+  hazards = birdResult.hazards
+  nextHazardId = birdResult.nextHazardId
+  events.push(...birdResult.events)
+  let hostileAdds = birdResult.hostileAdds
+
+  const target = getBossTarget(party)
+  if (boss.health <= 0 || !target) {
+    return withYianIndicators({
+      boss,
+      events,
+      hazards,
+      hostileAdds,
+      nextAddId,
+      nextHazardId,
+      nextProjectileId,
+      party,
+      projectiles,
+    })
+  }
+
+  if (boss.attackPhase === 'relocating') {
+    const nextPosition = clampVec2ToArena(
+      moveToward(boss.position, boss.relocateTarget, YIAN_CENTER_CHARGE_SPEED * dt),
+      boss.radius,
+      state.bounds,
+    )
+    boss = {
+      ...boss,
+      position: nextPosition,
+      velocity: scaleVec2(subtractVec2(nextPosition, boss.position), dt > 0 ? 1 / dt : 0),
+      facing: withFallbackFacing(subtractVec2(target.position, nextPosition), boss.facing),
+    }
+    if (distanceVec2(nextPosition, boss.relocateTarget) <= 4 || boss.phaseSecondsRemaining <= 0) {
+      boss = {
+        ...boss,
+        attackPhase: 'idle',
+        phaseSecondsRemaining: 0,
+        velocity: { x: 0, y: 0 },
+      }
+    }
+    return withYianIndicators({
+      boss,
+      events,
+      hazards,
+      hostileAdds,
+      nextAddId,
+      nextHazardId,
+      nextProjectileId,
+      party,
+      projectiles,
+    })
+  }
+
+  if (boss.attackPhase === 'fireballWindup') {
+    boss = {
+      ...boss,
+      facing: withFallbackFacing(subtractVec2(boss.fireballTarget, boss.position), boss.facing),
+    }
+    if (boss.phaseSecondsRemaining <= 0) {
+      const direction = withFallbackFacing(subtractVec2(boss.fireballTarget, boss.position), boss.facing)
+      projectiles.push({
+        id: `boss-projectile-${nextProjectileId}`,
+        sourceId: boss.id,
+        owner: 'boss',
+        projectileKind: 'fireball',
+        color: '#ff8b2b',
+        position: {
+          x: boss.position.x + direction.x * (boss.radius + YIAN_KUT_KU_BOSS_METADATA.fireballRadius! + 2),
+          y: boss.position.y + direction.y * (boss.radius + YIAN_KUT_KU_BOSS_METADATA.fireballRadius! + 2),
+        },
+        velocity: scaleVec2(direction, YIAN_KUT_KU_BOSS_METADATA.fireballSpeed!),
+        radius: YIAN_KUT_KU_BOSS_METADATA.fireballRadius!,
+        damage: YIAN_KUT_KU_BOSS_METADATA.fireballDamage!,
+        remainingSeconds: 7,
+        bouncesRemaining: YIAN_FIREBALL_BOUNCES,
+      })
+      nextProjectileId += 1
+      boss = {
+        ...boss,
+        attackPhase: 'fireballRecover',
+        phaseSecondsRemaining: 0.35,
+      }
+    }
+    return withYianIndicators({
+      boss,
+      events,
+      hazards,
+      hostileAdds,
+      nextAddId,
+      nextHazardId,
+      nextProjectileId,
+      party,
+      projectiles,
+    })
+  }
+
+  if (boss.attackPhase === 'fireballRecover' || boss.attackPhase === 'birdSummonRecover') {
+    if (boss.phaseSecondsRemaining <= 0) {
+      boss = { ...boss, attackPhase: 'idle', phaseSecondsRemaining: 0 }
+    }
+    return withYianIndicators({
+      boss,
+      events,
+      hazards,
+      hostileAdds,
+      nextAddId,
+      nextHazardId,
+      nextProjectileId,
+      party,
+      projectiles,
+    })
+  }
+
+  if (shouldYianRelocate(boss, state)) {
+    const center = yianCenterTarget(state)
+    boss = {
+      ...boss,
+      attackPhase: 'relocating',
+      phaseSecondsRemaining: 1.4,
+      relocateTarget: center,
+      chargeStart: { ...boss.position },
+      chargeEnd: center,
+      velocity: { x: 0, y: 0 },
+    }
+    return withYianIndicators({
+      boss,
+      events,
+      hazards,
+      hostileAdds,
+      nextAddId,
+      nextHazardId,
+      nextProjectileId,
+      party,
+      projectiles,
+    })
+  }
+
+  const nextThreshold = nextBirdWaveThreshold(boss)
+  if (nextThreshold !== undefined && boss.health / boss.maxHealth <= nextThreshold) {
+    const spawn = spawnBirdWave(state, nextAddId, boss.id, nextThreshold)
+    hostileAdds = [...hostileAdds, ...spawn.hostileAdds]
+    nextAddId = spawn.nextAddId
+    boss = {
+      ...boss,
+      attackPhase: 'birdSummonRecover',
+      birdWaveThresholdsTriggered: [...boss.birdWaveThresholdsTriggered, nextThreshold],
+      phaseSecondsRemaining: 0.55,
+    }
+    return withYianIndicators({
+      boss,
+      events,
+      hazards,
+      hostileAdds,
+      nextAddId,
+      nextHazardId,
+      nextProjectileId,
+      party,
+      projectiles,
+    })
+  }
+
+  if (boss.fireballCooldownRemaining <= 0) {
+    if (!isYianAtCenter(boss, state)) {
+      const center = yianCenterTarget(state)
+      boss = {
+        ...boss,
+        attackPhase: 'relocating',
+        phaseSecondsRemaining: 1.4,
+        relocateTarget: center,
+        chargeStart: { ...boss.position },
+        chargeEnd: center,
+        velocity: { x: 0, y: 0 },
+      }
+      return withYianIndicators({
+        boss,
+        events,
+        hazards,
+        hostileAdds,
+        nextAddId,
+        nextHazardId,
+        nextProjectileId,
+        party,
+        projectiles,
+      })
+    }
+
+    boss = {
+      ...boss,
+      attackPhase: 'fireballWindup',
+      fireballCooldownRemaining: YIAN_KUT_KU_BOSS_METADATA.fireballCooldown!,
+      fireballTarget: { ...target.position },
+      phaseSecondsRemaining: YIAN_KUT_KU_BOSS_METADATA.fireballWindup!,
+      velocity: { x: 0, y: 0 },
+    }
+    return withYianIndicators({
+      boss,
+      events,
+      hazards,
+      hostileAdds,
+      nextAddId,
+      nextHazardId,
+      nextProjectileId,
+      party,
+      projectiles,
+    })
+  }
+
+  const meleeResult = maybeApplyMelee(party, boss, target, state.time + dt)
+  party = meleeResult.party
+  boss = meleeResult.boss
+  events.push(...meleeResult.events)
+  if (meleeResult.events.length > 0) {
+    return withYianIndicators({
+      boss,
+      events,
+      hazards,
+      hostileAdds,
+      nextAddId,
+      nextHazardId,
+      nextProjectileId,
+      party,
+      projectiles,
+    })
+  }
+
+  const nextPosition = clampVec2ToArena(
+    moveToward(boss.position, yianApproachTarget(target, state), YIAN_KUT_KU_BOSS_METADATA.moveSpeed * dt),
+    boss.radius,
+    state.bounds,
+  )
+  boss = {
+    ...boss,
+    position: nextPosition,
+    velocity: scaleVec2(subtractVec2(nextPosition, boss.position), dt > 0 ? 1 / dt : 0),
+    facing: withFallbackFacing(subtractVec2(target.position, nextPosition), boss.facing),
+  }
+  return withYianIndicators({
+    boss,
+    events,
+    hazards,
+    hostileAdds,
+    nextAddId,
+    nextHazardId,
+    nextProjectileId,
+    party,
+    projectiles,
+  })
+}
+
+function shouldYianRelocate(
+  boss: Iwt2BossEntityState,
+  state: Iwt2ArenaState,
+): boolean {
+  return (
+    boss.position.x < YIAN_SAFE_WALL_MARGIN
+    || boss.position.x > state.bounds.width - YIAN_SAFE_WALL_MARGIN
+    || boss.position.y < YIAN_SAFE_WALL_MARGIN
+    || boss.position.y > state.bounds.height - YIAN_SAFE_WALL_MARGIN
+  )
+}
+
+function isYianAtCenter(boss: Iwt2BossEntityState, state: Iwt2ArenaState): boolean {
+  return distanceVec2(boss.position, yianCenterTarget(state)) <= YIAN_CENTER_CAST_DISTANCE
+}
+
+function yianApproachTarget(target: Iwt2PartyEntityState, state: Iwt2ArenaState): Iwt2Vec2 {
+  return clampVec2ToArena({
+    x: target.position.x + (target.position.x < state.bounds.width * 0.5 ? 190 : -190),
+    y: target.position.y + (target.position.y < state.bounds.height * 0.5 ? 96 : -96),
+  }, YIAN_KUT_KU_BOSS_METADATA.radius, state.bounds)
+}
+
+function yianCenterTarget(state: Iwt2ArenaState): Iwt2Vec2 {
+  return {
+    x: state.bounds.width * 0.5,
+    y: state.bounds.height * 0.5,
+  }
+}
+
+function tickYianBirds({
+  dt,
+  hazards,
+  nextHazardId,
+  party,
+  state,
+  time,
+}: {
+  dt: number
+  hazards: Iwt2GroundHazardState[]
+  nextHazardId: number
+  party: Iwt2PartyEntityState[]
+  state: Iwt2ArenaState
+  time: number
+}): {
+  hostileAdds: Iwt2HostileAddState[]
+  party: Iwt2PartyEntityState[]
+  hazards: Iwt2GroundHazardState[]
+  nextHazardId: number
+  events: Iwt2ArenaEvent[]
+} {
+  const events: Iwt2ArenaEvent[] = []
+  const hostileAdds: Iwt2HostileAddState[] = []
+  let nextParty = party
+  let nextHazards = hazards
+  let nextHazardIdValue = nextHazardId
+
+  for (const add of state.hostileAdds) {
+    if (add.health <= 0) continue
+    let nextAdd = {
+      ...add,
+      attackCooldownRemaining: Math.max(0, add.attackCooldownRemaining - dt),
+      flightCooldownRemaining: Math.max(0, add.flightCooldownRemaining - dt),
+      phaseSecondsRemaining: Math.max(0, add.phaseSecondsRemaining - dt),
+    }
+
+    if (nextAdd.attackPhase === 'flightWindup') {
+      if (nextAdd.phaseSecondsRemaining <= 0) {
+        nextAdd = {
+          ...nextAdd,
+          attackPhase: 'flying',
+          position: { ...nextAdd.flightStart },
+          velocity: scaleVec2(normalizeVec2(subtractVec2(nextAdd.flightEnd, nextAdd.flightStart)), YIAN_KUT_KU_BOSS_METADATA.birdFlightSpeed!),
+        }
+      }
+      hostileAdds.push(nextAdd)
+      continue
+    }
+
+    if (nextAdd.attackPhase === 'flying') {
+      const previousPosition = nextAdd.position
+      const nextPosition = moveToward(
+        nextAdd.position,
+        nextAdd.flightEnd,
+        YIAN_KUT_KU_BOSS_METADATA.birdFlightSpeed! * dt,
+      )
+      const shape = {
+        kind: 'lane' as const,
+        start: previousPosition,
+        end: nextPosition,
+        width: nextAdd.radius,
+      }
+      const hitMembers = nextParty.filter((member) => (
+        !nextAdd.flightHitEntityIds.includes(member.id)
+        && partyMemberIntersectsShape(member, shape)
+      ))
+      const hitResult = applyPartyDamageInShape(nextParty, shape, {
+        damage: BIRD_FLIGHT_DAMAGE,
+        excludedEntityIds: nextAdd.flightHitEntityIds,
+        knockdownSeconds: 0,
+        sourceId: nextAdd.id,
+        stunSeconds: YIAN_KUT_KU_BOSS_METADATA.birdStunSeconds!,
+        time,
+      })
+      nextParty = hitResult.party
+      events.push(...hitResult.events)
+      for (const member of hitMembers) {
+        const puddle = addFirePuddle({
+          damage: YIAN_KUT_KU_BOSS_METADATA.firePuddleDamage!,
+          duration: YIAN_KUT_KU_BOSS_METADATA.firePuddleSeconds!,
+          hazards: nextHazards,
+          nextHazardId: nextHazardIdValue,
+          position: member.position,
+          radius: YIAN_KUT_KU_BOSS_METADATA.firePuddleRadius!,
+          sourceId: nextAdd.id,
+          time,
+        })
+        nextHazards = puddle.hazards
+        nextHazardIdValue = puddle.nextHazardId
+      }
+
+      nextAdd = {
+        ...nextAdd,
+        flightHitEntityIds: [...nextAdd.flightHitEntityIds, ...hitResult.hitEntityIds],
+        position: nextPosition,
+        velocity: scaleVec2(subtractVec2(nextPosition, previousPosition), dt > 0 ? 1 / dt : 0),
+        facing: { x: 1, y: 0 },
+      }
+      if (distanceVec2(nextPosition, nextAdd.flightEnd) <= 1) {
+        nextAdd = {
+          ...nextAdd,
+          attackPhase: 'flightRecover',
+          flightCooldownRemaining: YIAN_KUT_KU_BOSS_METADATA.birdFlightCooldown!,
+          phaseSecondsRemaining: 0.4,
+          velocity: { x: 0, y: 0 },
+        }
+      }
+      hostileAdds.push(nextAdd)
+      continue
+    }
+
+    if (nextAdd.attackPhase === 'flightRecover') {
+      if (nextAdd.phaseSecondsRemaining <= 0) {
+        nextAdd = { ...nextAdd, attackPhase: 'idle', phaseSecondsRemaining: 0 }
+      }
+      hostileAdds.push(nextAdd)
+      continue
+    }
+
+    if (nextAdd.flightCooldownRemaining <= 0) {
+      hostileAdds.push(startBirdFlight(nextAdd, state, time))
+      continue
+    }
+
+    const target = getNearestPartyMember(nextParty, nextAdd.position)
+    if (!target) {
+      hostileAdds.push({ ...nextAdd, velocity: { x: 0, y: 0 } })
+      continue
+    }
+
+    const nextPosition = clampVec2ToArena(
+      moveToward(nextAdd.position, target.position, YIAN_KUT_KU_BOSS_METADATA.moveSpeed * 1.35 * dt),
+      nextAdd.radius,
+      state.bounds,
+    )
+    nextAdd = {
+      ...nextAdd,
+      position: nextPosition,
+      velocity: scaleVec2(subtractVec2(nextPosition, nextAdd.position), dt > 0 ? 1 / dt : 0),
+      facing: withFallbackFacing(subtractVec2(target.position, nextPosition), nextAdd.facing),
+    }
+    if (
+      nextAdd.attackCooldownRemaining <= 0
+      && distanceVec2(nextAdd.position, target.position) <= nextAdd.radius + target.radius + BIRD_MELEE_RANGE
+    ) {
+      const hitResult = applyPartyDamageInShape(nextParty, {
+        kind: 'circle',
+        position: nextAdd.position,
+        radius: nextAdd.radius + BIRD_MELEE_RANGE,
+      }, {
+        damage: YIAN_KUT_KU_BOSS_METADATA.birdContactDamage!,
+        sourceId: nextAdd.id,
+        time,
+      })
+      nextParty = hitResult.party
+      events.push(...hitResult.events)
+      nextAdd = { ...nextAdd, attackCooldownRemaining: BIRD_MELEE_COOLDOWN }
+    }
+    hostileAdds.push(nextAdd)
+  }
+
+  return {
+    events,
+    hazards: nextHazards,
+    hostileAdds,
+    nextHazardId: nextHazardIdValue,
+    party: nextParty,
+  }
+}
+
+function spawnBirdWave(
+  state: Iwt2ArenaState,
+  nextAddId: number,
+  sourceBossId: Iwt2BossId,
+  threshold: number,
+): { hostileAdds: Iwt2HostileAddState[], nextAddId: number } {
+  const hostileAdds: Iwt2HostileAddState[] = []
+  let nextId = nextAddId
+  for (let index = 0; index < BIRD_COUNT; index += 1) {
+    const y = birdLaneY(state, index, threshold * 100)
+    const radius = YIAN_KUT_KU_BOSS_METADATA.birdRadius!
+    const flightStart = { x: -radius - 8, y }
+    const flightEnd = { x: state.bounds.width + radius + 8, y }
+    hostileAdds.push({
+      id: `yian-bird-${nextId}`,
+      kind: 'hostileAdd',
+      addKind: 'yian-bird',
+      sourceBossId,
+      position: { ...flightStart },
+      velocity: { x: 0, y: 0 },
+      facing: { x: 1, y: 0 },
+      radius,
+      health: YIAN_KUT_KU_BOSS_METADATA.birdHealth!,
+      maxHealth: YIAN_KUT_KU_BOSS_METADATA.birdHealth!,
+      damageDone: 0,
+      attackCooldownRemaining: 0,
+      flightCooldownRemaining: YIAN_KUT_KU_BOSS_METADATA.birdFlightCooldown!,
+      attackPhase: 'flightWindup',
+      phaseSecondsRemaining: YIAN_KUT_KU_BOSS_METADATA.birdFlightWindup!,
+      flightStart,
+      flightEnd,
+      flightHitEntityIds: [],
+    })
+    nextId += 1
+  }
+  return { hostileAdds, nextAddId: nextId }
+}
+
+function startBirdFlight(add: Iwt2HostileAddState, state: Iwt2ArenaState, time: number): Iwt2HostileAddState {
+  const y = birdLaneY(state, Number(add.id.replace(/\D/g, '')) % BIRD_COUNT, time)
+  const flightStart = { x: -add.radius - 8, y }
+  const flightEnd = { x: state.bounds.width + add.radius + 8, y }
+  return {
+    ...add,
+    attackPhase: 'flightWindup',
+    phaseSecondsRemaining: YIAN_KUT_KU_BOSS_METADATA.birdFlightWindup!,
+    flightStart,
+    flightEnd,
+    flightHitEntityIds: [],
+    velocity: { x: 0, y: 0 },
+  }
+}
+
+function birdLaneY(state: Iwt2ArenaState, index: number, seed: number): number {
+  const laneHeight = state.bounds.height / (BIRD_COUNT + 1)
+  const base = laneHeight * (index + 1)
+  const wobble = Math.sin(seed * 8.37 + index * 2.1) * 34
+  return clamp(base + wobble, 58, state.bounds.height - 58)
+}
+
+function nextBirdWaveThreshold(boss: Iwt2BossEntityState): number | undefined {
+  return YIAN_KUT_KU_BOSS_METADATA.birdWaveThresholds
+    ?.find((threshold) => !boss.birdWaveThresholdsTriggered.includes(threshold))
+}
+
+function getBossTarget(party: Iwt2PartyEntityState[]): Iwt2PartyEntityState | undefined {
+  const livingTank = party.find((member) => member.classId === 'paladin' && member.health > 0)
+  if (livingTank) return livingTank
+  return party.find((member) => member.health > 0)
+}
+
+function getNearestPartyMember(party: Iwt2PartyEntityState[], position: Iwt2Vec2): Iwt2PartyEntityState | undefined {
+  let nearest: Iwt2PartyEntityState | undefined
+  let nearestDistance = Number.POSITIVE_INFINITY
+  for (const member of party) {
+    if (member.health <= 0) continue
+    const distance = distanceVec2(member.position, position)
+    if (distance < nearestDistance) {
+      nearest = member
+      nearestDistance = distance
+    }
+  }
+  return nearest
+}
+
+function maybeApplyMelee(
+  party: Iwt2PartyEntityState[],
+  boss: Iwt2BossEntityState,
+  target: Iwt2PartyEntityState,
+  time: number,
+): { boss: Iwt2BossEntityState, party: Iwt2PartyEntityState[], events: Iwt2ArenaEvent[] } {
+  if (boss.meleeCooldownRemaining > 0) return { boss, party, events: [] }
+  if (distanceVec2(boss.position, target.position) > YIAN_KUT_KU_BOSS_METADATA.meleeRange + target.radius) {
+    return { boss, party, events: [] }
+  }
+  const result = applyPartyDamageInShape(party, {
+    kind: 'circle',
+    position: boss.position,
+    radius: YIAN_KUT_KU_BOSS_METADATA.meleeRange,
+  }, {
+    damage: YIAN_KUT_KU_BOSS_METADATA.meleeDamage,
+    sourceId: boss.id,
+    time,
+  })
+  return {
+    boss: { ...boss, meleeCooldownRemaining: YIAN_KUT_KU_BOSS_METADATA.meleeCooldown },
+    party: result.party,
+    events: result.events,
+  }
+}
+
+function withYianIndicators(result: Omit<Iwt2YianTickResult, 'indicators'>): Iwt2YianTickResult {
+  return {
+    ...result,
+    indicators: createYianIndicators(result.boss, result.hostileAdds),
+  }
+}
+
+function createYianIndicators(
+  boss: Iwt2BossEntityState,
+  hostileAdds: Iwt2HostileAddState[],
+): Iwt2ArenaIndicator[] {
+  const indicators: Iwt2ArenaIndicator[] = []
+  if (boss.attackPhase === 'relocating') {
+    indicators.push(createLaneIndicator({
+      color: '#ffce5c',
+      end: boss.chargeEnd,
+      id: `${boss.id}:center-charge`,
+      mechanicId: 'yian-center-charge',
+      phase: 'active',
+      sourceId: boss.id,
+      start: boss.chargeStart,
+      width: boss.radius,
+    }))
+  }
+  if (boss.attackPhase === 'fireballWindup') {
+    indicators.push(createCircleIndicator({
+      color: '#ff8b2b',
+      id: `${boss.id}:fireball-cast`,
+      mechanicId: 'yian-fireball-cast',
+      phase: 'windup',
+      position: boss.position,
+      radius: boss.radius + 18,
+      sourceId: boss.id,
+    }))
+    indicators.push(createLaneIndicator({
+      color: '#ffb347',
+      end: boss.fireballTarget,
+      id: `${boss.id}:fireball-line`,
+      mechanicId: 'yian-fireball-line',
+      phase: 'windup',
+      sourceId: boss.id,
+      start: boss.position,
+      width: YIAN_KUT_KU_BOSS_METADATA.fireballRadius! + 4,
+    }))
+  }
+  for (const add of hostileAdds) {
+    if (
+      add.attackPhase !== 'flightWindup'
+      && add.attackPhase !== 'flying'
+      && add.attackPhase !== 'flightRecover'
+    ) {
+      continue
+    }
+    indicators.push(createLaneIndicator({
+      color: '#ffce5c',
+      end: add.flightEnd,
+      id: `${add.id}:flight-lane`,
+      mechanicId: 'yian-bird-flight',
+      phase: indicatorPhaseFromAttack(
+        add.attackPhase === 'flightWindup',
+        add.attackPhase === 'flying',
+      ),
+      sourceId: add.id,
+      start: add.flightStart,
+      width: add.radius,
+    }))
+  }
+  return indicators
+}