feat(advance-wars): add contextual battle and movement sound effects

- Assign battle sounds to each unit type (gunfire, tank, cannon, missile, etc.)
  and play the appropriate sound on attack/counterattack in battle animations
- Add per-unit-type movement sounds (march for infantry/mech, engine-fast,
  engine-heavy) that loop during move animations and stop cleanly on completion
- Play jump sound during capture animation hops and activation sound on capture
- Play explosion sound when units are defeated in combat or crash
- Lighten unit tint relative to buildings so units remain visually distinct
  when standing on captured buildings
- Add new audio assets: battle sounds, march, 8bit-jump, and update battle-tank

data/advancewars-artwork.json

@@ -23,5 +23,11 @@
     "path": null,
     "frameWidth": 48,
     "frameHeight": 48
+  },
+  "battleBgSheet": {
+    "key": "advancewars-battlebg",
+    "path": "assets/images/advancewars/advancewars-battlebg.png",
+    "frameWidth": 256,
+    "frameHeight": 256
   }
 }

data/advancewars-rules.json

@@ -317,6 +317,7 @@
   "units": [
     {
       "id": "infantry",
+      "battleSound": "gunfire-modern",
       "name": "Infantry",
       "abbr": "IN",
       "cost": 1000,
@@ -353,6 +354,7 @@
     },
     {
       "id": "recon",
+      "battleSound": "gunfire-modern",
       "name": "Recon",
       "abbr": "RC",
       "cost": 4000,
@@ -370,6 +372,7 @@
     },
     {
       "id": "tank",
+      "battleSound": "tank",
       "name": "Tank",
       "abbr": "TK",
       "cost": 7000,
@@ -387,6 +390,7 @@
     },
     {
       "id": "mdtank",
+      "battleSound": "cannon",
       "name": "Md Tank",
       "abbr": "MD",
       "cost": 16000,
@@ -404,6 +408,7 @@
     },
     {
       "id": "apc",
+      "battleSound": "gunfire-modern",
       "name": "APC",
       "abbr": "AP",
       "cost": 5000,
@@ -426,6 +431,7 @@
     },
     {
       "id": "artillery",
+      "battleSound": "cannon",
       "name": "Artillery",
       "abbr": "AR",
       "cost": 6000,
@@ -444,6 +450,7 @@
     },
     {
       "id": "rockets",
+      "battleSound": "missle",
       "name": "Rockets",
       "abbr": "RK",
       "cost": 15000,
@@ -462,6 +469,7 @@
     },
     {
       "id": "antiair",
+      "battleSound": "gunfire-modern",
       "name": "Anti-Air",
       "abbr": "AA",
       "cost": 8000,
@@ -479,6 +487,7 @@
     },
     {
       "id": "missiles",
+      "battleSound": "missle",
       "name": "Missiles",
       "abbr": "MS",
       "cost": 12000,
@@ -497,6 +506,7 @@
     },
     {
       "id": "fighter",
+      "battleSound": "gunfire-modern",
       "name": "Fighter",
       "abbr": "FT",
       "cost": 20000,
@@ -515,6 +525,7 @@
     },
     {
       "id": "bomber",
+      "battleSound": "cannon",
       "name": "Bomber",
       "abbr": "BM",
       "cost": 22000,
@@ -533,6 +544,7 @@
     },
     {
       "id": "bcopter",
+      "battleSound": "missle",
       "name": "B-Copter",
       "abbr": "BC",
       "cost": 9000,
@@ -551,6 +563,7 @@
     },
     {
       "id": "tcopter",
+      "battleSound": "helicopter",
       "name": "T-Copter",
       "abbr": "TC",
       "cost": 5000,
@@ -573,6 +586,7 @@
     },
     {
       "id": "battleship",
+      "battleSound": "cannon",
       "name": "Battleship",
       "abbr": "BS",
       "cost": 28000,
@@ -592,6 +606,7 @@
     },
     {
       "id": "cruiser",
+      "battleSound": "tank",
       "name": "Cruiser",
       "abbr": "CR",
       "cost": 18000,
@@ -617,6 +632,7 @@
     },
     {
       "id": "lander",
+      "battleSound": "missle",
       "name": "Lander",
       "abbr": "LD",
       "cost": 12000,
@@ -636,6 +652,7 @@
     },
     {
       "id": "sub",
+      "battleSound": "submarine",
       "name": "Sub",
       "abbr": "SB",
       "cost": 20000,

src/data/assetManifest.js

@@ -207,7 +207,13 @@ export const MANIFEST = {
     { type: 'json', key: 'advancewars-rules', path: 'data/advancewars-rules.json' },
     { type: 'json', key: 'advancewars-campaign', path: 'data/advancewars-campaign.json' },
     (scene) => sheetsFrom(scene, 'advancewars-artwork',
-      ['terrainSheet', 'buildingSheet', 'unitSheet', 'uiSheet']),
+      ['terrainSheet', 'buildingSheet', 'unitSheet', 'uiSheet', 'battleBgSheet']),
+    // Battle sounds keyed by each unit's `battleSound` in advancewars-rules.json
+    // (played on attack by playBattleAnim in AdvanceWarsBattleAnim.js).
+    ...['gunfire-modern', 'tank', 'cannon', 'helicopter', 'missle', 'submarine']
+      .map((n) => ({ type: 'audio', key: `sfx-battle-${n}`, path: `assets/fx/battle-${n}.mp3` })),
+    // Foot-unit march (infantry/mech), played on move in AdvanceWarsMapView.js.
+    { type: 'audio', key: 'sfx-march', path: 'assets/fx/march.mp3' },
     (scene) => musicFrom(scene, 'nintendo-music'),
   ],
   coloradodefense: [

src/games/advancewars/AdvanceWarsBattleAnim.js

@@ -4,16 +4,190 @@
 
 import { GAME_WIDTH, GAME_HEIGHT } from '../../config.js';
 import * as Logic from './AdvanceWarsLogic.js';
-import { armyColorInt } from './AdvanceWarsMapView.js';
+import { unitColorInt } from './AdvanceWarsMapView.js';
 import { FONT } from './AdvanceWarsUI.js';
+import { playSound } from '../../ui/Sounds.js';
 
 const W = 760;
 const H = 380;
 
+// ---------------------------------------------------------------------------
+// Battle backgrounds: one backdrop image per terrain/building a fighter can
+// stand on. Frame order (index i is frame i in the sheet, left-to-right,
+// top-to-bottom) — see sprites.md "Battle background sheet".
+export const BATTLE_BG_KEYS = [
+  'plain', 'wood', 'mountain', 'sea', 'reef',
+  'shoal', 'river', 'bridge', 'road',
+  'city', 'base', 'airport', 'port', 'hq',
+];
+const BG_FRAME = 256;
+const BG_COLS = 5;
+const BG_SHEET_KEY = 'advancewars-battlebg';
+
+// A property tile's own terrain id (city/base/airport/port/hq) already IS
+// its building type, so a unit standing on a building needs no separate
+// "terrain underneath" lookup — the tile only ever has one terrain id, and
+// that id already picks the right (building) background automatically.
+// bridgeh/bridgev share the single 'bridge' backdrop — orientation doesn't
+// matter for a static background behind a fighter.
+const TERRAIN_TO_BG = { bridgeh: 'bridge', bridgev: 'bridge' };
+
+export function battleBgFrame(terrainId) {
+  const key = TERRAIN_TO_BG[terrainId] ?? terrainId;
+  const i = BATTLE_BG_KEYS.indexOf(key);
+  return i < 0 ? BATTLE_BG_KEYS.indexOf('plain') : i;
+}
+
+// The engine has no separate "terrain underneath the building" value (a
+// tile only ever has one terrain id), so this is an editorial pick of what
+// a given building would plausibly sit on, used where a scene wants the
+// bare ground rather than the building's own backdrop (e.g. the capture
+// cut-in, which already shows the building itself as its squishing prop).
+const BUILDING_GROUND_TERRAIN = {
+  city: 'plain', base: 'plain', airport: 'plain', hq: 'plain', port: 'shoal',
+};
+
+export function groundBgFrame(terrainId) {
+  return battleBgFrame(BUILDING_GROUND_TERRAIN[terrainId] ?? terrainId);
+}
+
+// Painted sheet if loaded, else a generated stand-in with the same frame
+// map — mirrors the pattern in AdvanceWarsMapView.js's ensureSheets().
+export function ensureBattleBgSheet(scene) {
+  if (scene.textures.exists(BG_SHEET_KEY)) return BG_SHEET_KEY;
+  const procKey = `${BG_SHEET_KEY}-proc`;
+  if (!scene.textures.exists(procKey)) paintProceduralBattleBg(scene, procKey);
+  return procKey;
+}
+
+function paintProceduralBattleBg(scene, key) {
+  const cols = BG_COLS;
+  const rows = Math.ceil(BATTLE_BG_KEYS.length / cols);
+  const tex = scene.textures.createCanvas(key, cols * BG_FRAME, rows * BG_FRAME);
+  const ctx = tex.getContext();
+  const at = (i, draw) => {
+    ctx.save();
+    ctx.translate((i % cols) * BG_FRAME, Math.floor(i / cols) * BG_FRAME);
+    draw(ctx);
+    ctx.restore();
+  };
+  // simple sky/ground split backdrop, tinted per terrain; groundY is where
+  // the horizon sits (higher groundY = more sky visible, e.g. for water).
+  const skyGround = (sky, ground, groundY = 150) => (c) => {
+    c.fillStyle = sky; c.fillRect(0, 0, BG_FRAME, BG_FRAME);
+    c.fillStyle = ground; c.fillRect(0, groundY, BG_FRAME, BG_FRAME - groundY);
+  };
+  const SKY = '#bfe0f0';
+
+  at(BATTLE_BG_KEYS.indexOf('plain'), skyGround(SKY, '#a8d060'));
+
+  at(BATTLE_BG_KEYS.indexOf('wood'), (c) => {
+    skyGround(SKY, '#8cc456')(c);
+    c.fillStyle = '#2f6b22';
+    for (const [tx, ty] of [[60, 150], [150, 130], [200, 160], [90, 190]]) {
+      c.beginPath(); c.moveTo(tx - 30, ty + 60); c.lineTo(tx + 30, ty + 60); c.lineTo(tx, ty - 30); c.fill();
+      c.fillRect(tx - 8, ty + 60, 16, 20);
+    }
+  });
+
+  at(BATTLE_BG_KEYS.indexOf('mountain'), (c) => {
+    skyGround(SKY, '#b5d16b')(c);
+    c.fillStyle = '#8a6a3c';
+    c.beginPath(); c.moveTo(20, 240); c.lineTo(128, 40); c.lineTo(236, 240); c.fill();
+    c.fillStyle = '#f0ede2';
+    c.beginPath(); c.moveTo(100, 90); c.lineTo(128, 40); c.lineTo(156, 90); c.lineTo(128, 108); c.fill();
+  });
+
+  at(BATTLE_BG_KEYS.indexOf('sea'), (c) => {
+    skyGround(SKY, '#3d6fd6', 60)(c);
+    c.strokeStyle = '#6f9ae8'; c.lineWidth = 4;
+    for (let i = 0; i < 4; i++) {
+      c.beginPath(); c.moveTo(10, 110 + i * 36); c.quadraticCurveTo(70, 90 + i * 36, 130, 110 + i * 36);
+      c.quadraticCurveTo(190, 130 + i * 36, 246, 110 + i * 36); c.stroke();
+    }
+  });
+
+  at(BATTLE_BG_KEYS.indexOf('reef'), (c) => {
+    skyGround(SKY, '#3d6fd6', 60)(c);
+    c.fillStyle = '#24488f';
+    for (const [px, py] of [[60, 140], [150, 110], [110, 190], [200, 170], [180, 220]]) {
+      c.beginPath(); c.arc(px, py, 20, 0, 7); c.fill();
+    }
+  });
+
+  at(BATTLE_BG_KEYS.indexOf('shoal'), (c) => {
+    c.fillStyle = SKY; c.fillRect(0, 0, BG_FRAME, BG_FRAME);
+    c.fillStyle = '#8fb8e8'; c.fillRect(0, 90, BG_FRAME, 40);
+    c.fillStyle = '#e8d9a0'; c.fillRect(0, 130, BG_FRAME, BG_FRAME - 130);
+  });
+
+  at(BATTLE_BG_KEYS.indexOf('river'), (c) => {
+    skyGround(SKY, '#3d6fd6', 130)(c);
+    c.strokeStyle = '#6f9ae8'; c.lineWidth = 4;
+    for (let i = 0; i < 3; i++) {
+      c.beginPath(); c.moveTo(20, 170 + i * 32); c.quadraticCurveTo(128, 150 + i * 32, 236, 170 + i * 32); c.stroke();
+    }
+  });
+
+  at(BATTLE_BG_KEYS.indexOf('bridge'), (c) => {
+    skyGround(SKY, '#3d6fd6', 60)(c);
+    c.fillStyle = '#b0a89a'; c.fillRect(0, 150, BG_FRAME, 60);
+    c.fillStyle = '#8a8276';
+    for (let x = 10; x < BG_FRAME; x += 26) c.fillRect(x, 150, 6, 60);
+  });
+
+  at(BATTLE_BG_KEYS.indexOf('road'), (c) => {
+    skyGround(SKY, '#d8cfc0')(c);
+    c.fillStyle = '#a89c88'; c.fillRect(0, 150, BG_FRAME, 8);
+  });
+
+  const building = (icon) => (c) => {
+    skyGround(SKY, '#a8d060')(c);
+    c.fillStyle = '#ececec'; c.strokeStyle = '#3a3a3a'; c.lineWidth = 3;
+    c.fillRect(48, 30, 160, 190); c.strokeRect(48, 30, 160, 190);
+    icon(c);
+  };
+  at(BATTLE_BG_KEYS.indexOf('city'), building((c) => {
+    c.fillStyle = '#8a8a8a';
+    c.fillRect(72, 60, 42, 130); c.fillRect(140, 90, 42, 100);
+    c.fillStyle = '#3a3a3a';
+    for (let i = 0; i < 4; i++) { c.fillRect(80, 70 + i * 28, 26, 12); c.fillRect(148, 100 + i * 22, 26, 10); }
+  }));
+  at(BATTLE_BG_KEYS.indexOf('base'), building((c) => {
+    c.fillStyle = '#8a8a8a';
+    c.fillRect(64, 100, 128, 80);
+    c.beginPath(); c.moveTo(64, 100); c.lineTo(96, 40); c.lineTo(128, 100); c.lineTo(160, 40); c.lineTo(192, 100); c.fill();
+    c.fillStyle = '#3a3a3a'; c.fillRect(112, 130, 32, 50);
+  }));
+  at(BATTLE_BG_KEYS.indexOf('airport'), building((c) => {
+    c.fillStyle = '#8a8a8a';
+    c.beginPath();
+    c.moveTo(128, 30); c.lineTo(148, 70); c.lineTo(200, 90); c.lineTo(148, 110);
+    c.lineTo(128, 170); c.lineTo(108, 110); c.lineTo(56, 90); c.lineTo(108, 70); c.fill();
+  }));
+  at(BATTLE_BG_KEYS.indexOf('port'), building((c) => {
+    c.strokeStyle = '#8a8a8a'; c.lineWidth = 18;
+    c.beginPath(); c.arc(128, 100, 46, 0.5, Math.PI - 0.5, false); c.stroke();
+    c.beginPath(); c.moveTo(128, 30); c.lineTo(128, 130); c.stroke();
+    c.beginPath(); c.moveTo(96, 55); c.lineTo(160, 55); c.stroke();
+  }));
+  at(BATTLE_BG_KEYS.indexOf('hq'), building((c) => {
+    c.fillStyle = '#8a8a8a'; c.fillRect(108, 20, 18, 170);
+    c.fillStyle = '#e05050';
+    c.beginPath(); c.moveTo(126, 24); c.lineTo(200, 50); c.lineTo(126, 76); c.fill();
+  }));
+
+  tex.refresh();
+  for (let i = 0; i < BATTLE_BG_KEYS.length; i++) {
+    tex.add(i, 0, (i % cols) * BG_FRAME, Math.floor(i / cols) * BG_FRAME, BG_FRAME, BG_FRAME);
+  }
+}
+
 // battles: array of engine 'battle' events (1 or 2 volleys).
 // Shows attacker left, defender right; each volley flashes and drains HP.
-// texKey is the unit sheet (painted or procedural).
-export function playBattleAnim(scene, rules, texKey, battles, onDone) {
+// texKey is the unit sheet (painted or procedural). state resolves the
+// terrain each fighter is standing on, to pick their backdrop image.
+export function playBattleAnim(scene, rules, state, texKey, battles, onDone) {
   if (!battles.length) { onDone?.(); return null; }
   const cx = GAME_WIDTH / 2 - 130, cy = GAME_HEIGHT / 2 - 40;
   const objs = [];
@@ -28,19 +202,26 @@ export function playBattleAnim(scene, rules, texKey, battles, onDone) {
     .setDepth(50).setInteractive();
   const panel = scene.add.rectangle(cx, cy, W, H, 0x10141f, 0.97)
     .setStrokeStyle(3, 0x3a4260).setDepth(50);
-  const split = scene.add.rectangle(cx, cy, 4, H, 0x3a4260, 1).setDepth(50);
-  objs.push(dim, panel, split);
+  objs.push(dim, panel);
 
-  const ground = (side, color) => scene.add
-    .rectangle(cx + side * W / 4, cy + H / 2 - 40, W / 2 - 8, 80, color, 1).setDepth(50);
-  objs.push(ground(-1, 0x27324a), ground(1, 0x27324a));
+  // backdrop per side — the terrain/building each fighter is actually
+  // standing on (property tiles' own terrain id already IS their building
+  // type, so no separate override lookup is needed, see battleBgFrame).
+  const bgSheet = ensureBattleBgSheet(scene);
+  const backdrop = (side, info) => scene.add
+    .image(cx + side * W / 4, cy, bgSheet, battleBgFrame(Logic.terrainAt(rules, state, info.x, info.y).id))
+    .setDisplaySize(W / 2 - 6, H - 6).setFlipX(side > 0).setDepth(50.3);
+  objs.push(backdrop(-1, leftSide), backdrop(1, rightSide));
+
+  const split = scene.add.rectangle(cx, cy, 4, H, 0x3a4260, 1).setDepth(50.6);
+  objs.push(split);
 
   const mkFighter = (side, info) => {
     const spec = rules.unitById[info.type];
     const img = scene.add.image(cx + side * W / 4, cy + H / 2 - 78, texKey, spec.frame)
       .setScale(3.4).setOrigin(0.5, 1).setDepth(51)
       .setFlipX(side > 0)
-      .setTint(armyColorInt(rules, info.army));
+      .setTint(unitColorInt(rules, info.army));
     objs.push(img);
     const label = scene.add.text(cx + side * W / 4, cy - H / 2 + 26,
       spec.name, { fontFamily: FONT, fontSize: '26px', color: '#ffffff' })
@@ -97,6 +278,10 @@ export function playBattleAnim(scene, rules, texKey, battles, onDone) {
     const victim = fromLeft ? right : left;
     timers.push(scene.time.delayedCall(delay, () => {
       if (finished) return;
+      // keyed by the shooter for THIS volley, not the initial attacker —
+      // a counterattack is fired by the defender's own unit type.
+      const battleSound = rules.unitById[b.attacker.type]?.battleSound;
+      if (battleSound) playSound(scene, `sfx-battle-${battleSound}`);
       scene.tweens.add({
         targets: shooter.img, x: shooter.img.x + (fromLeft ? 40 : -40),
         duration: 150, yoyo: true,

src/games/advancewars/AdvanceWarsCaptureAnim.js

@@ -6,8 +6,10 @@
 
 import { GAME_WIDTH, GAME_HEIGHT } from '../../config.js';
 import * as Logic from './AdvanceWarsLogic.js';
-import { armyColorInt } from './AdvanceWarsMapView.js';
+import { armyColorInt, unitColorInt } from './AdvanceWarsMapView.js';
 import { FONT } from './AdvanceWarsUI.js';
+import { ensureBattleBgSheet, groundBgFrame } from './AdvanceWarsBattleAnim.js';
+import { playSound, SFX } from '../../ui/Sounds.js';
 
 const W = 380;
 const H = 500;
@@ -41,10 +43,17 @@ export function playCaptureAnim(scene, rules, view, capturing, captured, onDone)
     .setStrokeStyle(3, 0x3a4260).setDepth(50);
   objs.push(dim, panel);
 
+  // backdrop is the terrain the building itself sits on (plain/shoal/etc),
+  // not the building's own battle background — the building is already the
+  // scene's main squishing prop, so showing its backdrop too would just be
+  // a duplicate building rendered twice.
+  const bgSheet = ensureBattleBgSheet(scene);
+  const backdrop = scene.add.image(cx, cy, bgSheet, groundBgFrame(t.id))
+    .setDisplaySize(W - 6, H - 6).setDepth(50.3);
+  objs.push(backdrop);
+
   const groundCenterY = cy + H / 2 - 50;
-  const ground = scene.add.rectangle(cx, groundCenterY, W - 60, 80, 0x27324a, 1).setDepth(50);
-  objs.push(ground);
-  const groundY = groundCenterY - 40; // top edge of the ground strip
+  const groundY = groundCenterY - 40; // where the building's base sits
 
   const label = scene.add.text(cx, cy - H / 2 + 30, (t.name ?? 'Property').toUpperCase(),
     { fontFamily: FONT, fontSize: '26px', color: '#ffffff' }).setOrigin(0.5, 0.5).setDepth(51);
@@ -61,7 +70,7 @@ export function playCaptureAnim(scene, rules, view, capturing, captured, onDone)
   const unitImg = scene.add.image(cx, groundY - building.displayHeight, view.tex.units, spec.frame)
     .setOrigin(0.5, 1).setScale(UNIT_SCALE).setDepth(52)
     .setFlipX(unit.army !== 0)
-    .setTint(armyColorInt(rules, unit.army));
+    .setTint(unitColorInt(rules, unit.army));
   objs.push(unitImg);
 
   // large capture-points counter, floating to the unit's left, always
@@ -97,6 +106,7 @@ export function playCaptureAnim(scene, rules, view, capturing, captured, onDone)
   function phase3raise() {
     if (finished) return;
     building.setTint(armyColorInt(rules, captured.army));
+    playSound(scene, SFX.EIGHTBIT_MOVE);
     scene.tweens.add({
       targets: building, scaleY: BUILDING_SCALE, duration: 500, ease: 'Sine.easeOut',
       onUpdate: () => { unitImg.y = restY(); trackUnit(); pointsText.setText(String(currentPoints())); },
@@ -119,9 +129,14 @@ export function playCaptureAnim(scene, rules, view, capturing, captured, onDone)
     });
   }
 
-  // 1.5s: two hops in place atop the (pre-squish) building height.
+  // 1.5s: two hops in place atop the (pre-squish) building height. A jump
+  // sound fires as each hop leaves the ground — once on start, once again
+  // when the repeat kicks off the second hop.
+  const jumpSound = () => playSound(scene, SFX.EIGHTBIT_JUMP);
   scene.tweens.add({
     targets: unitImg, y: restY() - HOP, duration: 375, yoyo: true, repeat: 1, ease: 'Sine.easeOut',
+    onStart: jumpSound,
+    onRepeat: jumpSound,
     onUpdate: trackUnit,
     onComplete: phase2squish,
   });

src/games/advancewars/AdvanceWarsGame.js

@@ -424,7 +424,7 @@ export default class AdvanceWarsGame extends Phaser.Scene {
     const run = this.run;
     run.mode = 'target';
     run.targets = targets;
-    run.view.showAttackTiles(targets.map((t) => ({ x: t.x, y: t.y })));
+    run.view.showAttackTiles(targets.map((t) => ({ x: t.x, y: t.y })), { pulse: true });
   }
 
   onTargetClick(tile) {
@@ -529,7 +529,7 @@ export default class AdvanceWarsGame extends Phaser.Scene {
         const anyVisible = !run.state.fog || battles.some((b) =>
           Logic.computeVision(this.rules, run.state, 0).has(Logic.tileKey(run.state, b.defender.x, b.defender.y)));
         if (this.battleAnims && anyVisible) {
-          await new Promise((resolve) => playBattleAnim(this, this.rules, run.view.tex.units, battles, resolve));
+          await new Promise((resolve) => playBattleAnim(this, this.rules, run.state, run.view.tex.units, battles, resolve));
         }
         this.crt.pulse(0.6, 260);
       }

src/games/advancewars/AdvanceWarsMapView.js

@@ -11,6 +11,7 @@
 
 import * as Phaser from 'phaser';
 import * as Logic from './AdvanceWarsLogic.js';
+import { playSound, SFX } from '../../ui/Sounds.js';
 
 const CELL = 48;
 const TALL = 64; // building/unit cells: 48×48 footprint + 16px headroom
@@ -27,6 +28,15 @@ const UNIT_DEPTH_BIAS = 0.5;
 // building rather than floating disconnected from it.
 const PROP_NUMBER_OVERLAP = 5;
 
+// Per-unit-type movement sound, looped for however long the move animation
+// takes and stopped the instant it ends (see animateMove).
+const MOVE_SOUND_BY_TYPE = {
+  infantry: 'sfx-march', mech: 'sfx-march',
+  tank: 'sfx-engine-heavy', mdtank: 'sfx-engine-heavy', artillery: 'sfx-engine-heavy',
+  rockets: 'sfx-engine-heavy', missiles: 'sfx-engine-heavy', bomber: 'sfx-engine-heavy',
+  recon: 'sfx-engine-fast', apc: 'sfx-engine-fast', antiair: 'sfx-engine-fast', fighter: 'sfx-engine-fast',
+};
+
 // Painted drop-in sheets and the layout their procedural stand-ins mirror.
 export const SHEETS = {
   terrain: { key: 'advancewars-terrain', cellH: CELL, cols: 8, frames: 8 },
@@ -44,6 +54,12 @@ export function armyColorInt(rules, army) {
   return parseInt(hex.slice(1), 16);
 }
 
+// Units render a little lighter than buildings of the same army, so the two
+// stay visually distinguishable when a unit is standing on a building.
+export function unitColorInt(rules, army) {
+  return lighten(armyColorInt(rules, army), 0.48);
+}
+
 // ---------------------------------------------------------------------------
 // Procedural stand-in sheets
 
@@ -246,6 +262,7 @@ export class AdvanceWarsMapView {
 
   destroy() {
     this.flipTimer?.remove();
+    this.atkPulseTween?.stop();
     this.rt?.destroy();
     this.moveG?.destroy(); this.atkG?.destroy(); this.fogG?.destroy();
     this.pathG?.destroy(); this.cursor?.destroy();
@@ -460,7 +477,7 @@ export class AdvanceWarsMapView {
     v.c.setPosition(this.px(u.x), this.oy + (u.y + 1) * this.tile).setDepth(this.depths.actors + u.y + UNIT_DEPTH_BIAS);
     v.sprite.setFrame(rules.unitById[u.type].frame + this.animStep);
     v.sprite.setFlipX(u.army !== 0);
-    const base = armyColorInt(rules, u.army);
+    const base = unitColorInt(rules, u.army);
     v.sprite.setTint(u.moved && u.army === this.state.turn ? darken(base, 0.5) : base);
     v.sprite.setAlpha(u.dived ? 0.5 : 1);
     const hpd = Logic.hpDisplay(u);
@@ -492,15 +509,42 @@ export class AdvanceWarsMapView {
     }
   }
 
-  showAttackTiles(tiles) {
+  // pulse: true for "you must pick a target now" (entering FIRE target mode)
+  // — red fill + white border breathing to draw the eye. false (default)
+  // keeps the old static tint, used for the indirect-range preview shown
+  // while a unit is merely selected, before a move/target is committed to.
+  showAttackTiles(tiles, { pulse = false } = {}) {
+    this.atkPulseTween?.stop();
+    this.atkPulseTween = null;
     this.atkG.clear();
-    this.atkG.fillStyle(0xff3d3d, 0.42);
-    for (const { x, y } of tiles) {
-      this.atkG.fillRect(this.ox + x * this.tile + 1, this.oy + y * this.tile + 1, this.tile - 2, this.tile - 2);
+    if (!pulse) {
+      this.atkG.fillStyle(0xff3d3d, 0.42);
+      for (const { x, y } of tiles) {
+        this.atkG.fillRect(this.ox + x * this.tile + 1, this.oy + y * this.tile + 1, this.tile - 2, this.tile - 2);
+      }
+      return;
     }
+    const draw = (fillA, lineA) => {
+      this.atkG.clear();
+      this.atkG.fillStyle(0xff3d3d, fillA);
+      this.atkG.lineStyle(Math.max(2, this.tile * 0.06), 0xffffff, lineA);
+      for (const { x, y } of tiles) {
+        const px = this.ox + x * this.tile + 1, py = this.oy + y * this.tile + 1, s = this.tile - 2;
+        this.atkG.fillRect(px, py, s, s);
+        this.atkG.strokeRect(px, py, s, s);
+      }
+    };
+    const phase = { t: 0 };
+    draw(0.30, 0.55);
+    this.atkPulseTween = this.scene.tweens.add({
+      targets: phase, t: 1, duration: 550, yoyo: true, repeat: -1, ease: 'Sine.easeInOut',
+      onUpdate: () => draw(0.28 + phase.t * 0.34, 0.5 + phase.t * 0.5),
+    });
   }
 
   clearOverlays() {
+    this.atkPulseTween?.stop();
+    this.atkPulseTween = null;
     this.moveG.clear();
     this.atkG.clear();
     this.pathG.clear();
@@ -549,10 +593,12 @@ export class AdvanceWarsMapView {
     this.setUnitVisibility(spotted);
   }
 
-  // quick explosion puff at a tile
+  // quick explosion puff at a tile — plays whenever a unit is defeated
+  // (destroyed in combat or crashed), regardless of the battleAnims toggle.
   boom(x, y, onDone) {
     const img = this.scene.add.image(this.px(x), this.py(y), this.tex.ui, UI_FRAMES.explosion1)
       .setScale(this.spriteScaleFor()).setDepth(this.depths.cursor);
+    playSound(this.scene, SFX.BATTLESHIP_HIT);
     this.scene.time.delayedCall(200, () => img.setFrame(UI_FRAMES.explosion2));
     this.scene.time.delayedCall(450, () => { img.destroy(); onDone?.(); });
   }
@@ -561,10 +607,27 @@ export class AdvanceWarsMapView {
   animateMove(unitId, path, onDone) {
     const v = this.unitViews.get(unitId);
     if (!v || !path?.length) { onDone?.(); return; }
+    const unit = Logic.unitById(this.state, unitId);
+    // loops for however long the move takes (covers paths longer than one
+    // clip) and is stopped the instant the path finishes — never allowed to
+    // ring on past the move or get cut short mid-loop.
+    let moveSound = null;
+    const moveSoundKey = unit && MOVE_SOUND_BY_TYPE[unit.type];
+    if (moveSoundKey) {
+      try {
+        moveSound = this.scene.sound.add(moveSoundKey, { loop: true });
+        moveSound.play();
+      } catch (_) { moveSound = null; }
+    }
     const points = path.map((s) => ({ x: this.px(s.x), y: this.oy + (s.y + 1) * this.tile, row: s.y }));
     let i = 0;
     const step = () => {
-      if (i >= points.length) { onDone?.(); return; }
+      if (i >= points.length) {
+        moveSound?.stop();
+        moveSound?.destroy();
+        onDone?.();
+        return;
+      }
       const p = points[i++];
       v.c.setDepth(this.depths.actors + p.row + UNIT_DEPTH_BIAS);
       this.scene.tweens.add({

src/games/advancewars/sprites.md

@@ -1,13 +1,17 @@
 # Advance Wars — spritesheet spec
 
-Art is split into **four independent sheets**, one per category, so each can
+Art is split into **five independent sheets**, one per category, so each can
 be painted and dropped in separately. Until a sheet is painted, the game
 renders a procedural stand-in with the exact same frame map — everything is
 fully playable art-free, and you can drop in one sheet at a time.
 
-**Rivers and roads need NO art**: they are drawn in code (Graphics) from
-tile connection masks, so there are no variant frames to paint. Shoreline
-foam where sea meets land is also drawn in code.
+**Rivers and roads need NO art on the map itself**: they are drawn in code
+(Graphics) from tile connection masks, so there are no variant frames to
+paint for the *terrain sheet*. Shoreline foam where sea meets land is also
+drawn in code. This exemption does **not** extend to the battle background
+sheet (§5) — that one needs a full backdrop scene for every occupiable
+terrain, river/road/bridge included, since it's a standalone illustration
+rather than a tileable ground texture.
 
 ## Drop-in procedure (no code changes)
 
@@ -108,7 +112,49 @@ spare).** Full color, transparent background.
 Icons 3–6 render at roughly 40% tile size as unit badges; keep them bold
 and readable when small.
 
-## Game icon
+## 5. Battle background sheet — `advancewars-battlebg.png`
+
+**256×256 cells, 5 columns × 3 rows = 1280×768 px (14 frames used, last cell
+spare).** Full color, full-bleed illustration — no transparency needed,
+these fill the entire backdrop behind each fighter in the battle cut-in
+window (`AdvanceWarsBattleAnim.js`). Landscape/scene paintings, not tile
+icons: think "diorama behind the two combatants," not "48×48 ground swatch."
+
+One frame per terrain type a unit can actually stand on, **plus** one per
+building type. A property tile's own terrain id (city/base/airport/port/hq)
+*is* its building type — there's no separate "terrain underneath the
+building" to paint over, since a tile only ever has one terrain value at a
+time. So each frame below is a straight lookup, not a layered composite.
+
+| frame | content |
+|-------|---------|
+| 0 | Plain (grass field) |
+| 1 | Wood (forest clearing) |
+| 2 | Mountain |
+| 3 | Sea (open water) |
+| 4 | Reef (rocky shallows) |
+| 5 | Shoal (beach) |
+| 6 | River |
+| 7 | Bridge — used for **both** horizontal and vertical bridge tiles; orientation doesn't matter for a static backdrop, so this one frame covers both `bridgeh` and `bridgev` |
+| 8 | Road |
+| 9 | City |
+| 10 | Base (land factory) |
+| 11 | Airport |
+| 12 | Port |
+| 13 | HQ |
+
+Each fighter's backdrop is picked by looking up the terrain tile they're
+actually standing on when the battle happens (from the engine's `battle`
+event coordinates) — so, e.g., a tank parked on a captured city shows the
+City background, not Plain, even though a tank could also be fought on open
+grass elsewhere. The defender's backdrop is horizontally mirrored (matching
+the mirrored defender unit sprite) — avoid art with strong left/right
+asymmetry (e.g. a building silhouette that visibly leans one way) unless
+you're fine with it flipping on the right-hand side.
+
+Unlike the other four sheets, this one is painted in full color and is
+**not tinted** — buildings here don't need to react to owner army color
+the way the small map-icon building sheet does.
 
 Also paint **frame 86 of `assets/images/game-icons.png`** (44×44, row 5
 col 11 of that 15-per-row sheet). Suggested motif: a small orange tank on a

src/scenes/PreloadScene.js

@@ -137,6 +137,7 @@ export default class PreloadScene extends Phaser.Scene {
     this.load.audio('sfx-8bit-activate', 'assets/fx/8bit-activate.mp3');
     this.load.audio('sfx-8bit-action',   'assets/fx/8bit-action.mp3');
     this.load.audio('sfx-8bit-move',     'assets/fx/8bit-move.mp3');
+    this.load.audio('sfx-8bit-jump',     'assets/fx/8bit-jump.mp3');
     this.load.audio('sfx-8bit-explode',  'assets/fx/8bit-explode.mp3');
     this.load.audio('sfx-8bit-explode2', 'assets/fx/8bit-explode2.mp3');
     this.load.audio('sfx-8bit-count',    'assets/fx/8bit-count.mp3');

src/ui/Sounds.js

@@ -44,6 +44,7 @@ export const SFX = {
   EIGHTBIT_ACTIVATE:     'sfx-8bit-activate',
   EIGHTBIT_ACTION:       'sfx-8bit-action',
   EIGHTBIT_MOVE:         'sfx-8bit-move',
+  EIGHTBIT_JUMP:         'sfx-8bit-jump',
   EIGHTBIT_CARD:         'sfx-card-deal-8bit',
   EIGHTBIT_EXPLODE:      'sfx-8bit-explode',
   EIGHTBIT_EXPLODE_2:    'sfx-8bit-explode2',