/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");
var facekit = LK.import("@upit/facekit.v1");

/**** 
* Classes
****/ 
// Ball class: the fixed shooter at bottom left
var Ball = Container.expand(function () {
	var self = Container.call(this);
	var ballAsset = self.attachAsset('ball', {
		anchorX: 0.5,
		anchorY: 0.5,
		width: BALL_SIZE,
		height: BALL_SIZE,
		color: 0xffffff,
		shape: 'ellipse'
	});
	return self;
});
// Bullet class: fired from ball towards crosshair
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletAsset = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5,
		width: BULLET_SIZE,
		height: BULLET_SIZE,
		color: 0x00e6e6,
		shape: 'ellipse'
	});
	self.vx = 0;
	self.vy = 0;
	self.update = function () {
		self.x += self.vx;
		self.y += self.vy;
	};
	return self;
});
// Crosshair class: follows facekit position
var Crosshair = Container.expand(function () {
	var self = Container.call(this);
	var crossAsset = self.attachAsset('crosshair', {
		anchorX: 0.5,
		anchorY: 0.5,
		width: CROSS_SIZE,
		height: CROSS_SIZE,
		color: 0xff0000,
		shape: 'ellipse'
	});
	return self;
});
// MusicNoteEffect class: floating music note symbol when a note is hit
var MusicNoteEffect = Container.expand(function () {
	var self = Container.call(this);
	// Use a Text2 object for the music note symbol
	var noteSymbol = new Text2("♪", {
		size: 120,
		fill: "#fff"
	});
	noteSymbol.anchor.set(0.5, 0.5);
	self.addChild(noteSymbol);
	// Animate: float up and fade out
	self.start = function (startX, startY) {
		self.x = startX;
		self.y = startY;
		self.alpha = 1;
		// Tween upward and fade out
		tween(self, {
			y: self.y - 220,
			alpha: 0
		}, {
			duration: 700,
			easing: tween.cubicOut,
			onFinish: function onFinish() {
				self.destroy();
			}
		});
	};
	return self;
});
// Note class: falling note
var Note = Container.expand(function () {
	var self = Container.call(this);
	// Randomly pick a color for the note
	var color = NOTE_COLORS[Math.floor(Math.random() * NOTE_COLORS.length)];
	var noteAsset = self.attachAsset('note', {
		anchorX: 0.5,
		anchorY: 0.5,
		width: NOTE_WIDTH,
		// now wider
		height: NOTE_HEIGHT,
		color: color,
		shape: 'box'
	});
	self.column = 0; // which column this note is in
	self.speed = noteFallSpeed; // will be set on spawn
	self.hit = false; // has this note been hit
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x181a20
});

/**** 
* Game Code
****/ 
// Note: All note assets will be ellipses with different colors for variety
// --- Constants ---
var NOTE_COLORS = [0xffe066, 0x66b3ff, 0xff66a3, 0x7cff66, 0xff8c66];
var GAME_W = 2048;
var GAME_H = 2732;
// --- Dynamic Gradient Background ---
// We'll use two large colored rectangles, tweening their tints and alpha for a subtle animated gradient effect.
var bgLayer1 = null;
var bgLayer2 = null;
var bgGradientColors = [0x8635f1,
// purple
0x66b3ff,
// blue
0xff66a3,
// pink
0x7cff66,
// green
0xffe066,
// yellow
0xb39ddb // lavender
];
var bgColorIdx1 = 0;
var bgColorIdx2 = 1;
var bgTweenDuration = 8000; // ms, slightly longer for smoother transitions
function setupGradientBackground() {
	// Remove if already present
	if (bgLayer1) {
		bgLayer1.destroy();
		bgLayer1 = null;
	}
	if (bgLayer2) {
		bgLayer2.destroy();
		bgLayer2 = null;
	}
	// Layer 1
	bgLayer1 = LK.getAsset('softbg2', {
		anchorX: 0.5,
		anchorY: 0.5,
		width: GAME_W * 1.1,
		height: GAME_H * 1.1,
		x: GAME_W / 2,
		y: GAME_H / 2,
		// Start with first color, slightly more visible
		tint: bgGradientColors[bgColorIdx1],
		alpha: 0.32
	});
	// Layer 2
	bgLayer2 = LK.getAsset('softbg2', {
		anchorX: 0.5,
		anchorY: 0.5,
		width: GAME_W * 1.1,
		height: GAME_H * 1.1,
		x: GAME_W / 2,
		y: GAME_H / 2,
		// Start with second color, slightly more visible
		tint: bgGradientColors[bgColorIdx2],
		alpha: 0.22
	});
	// Add to back of display list
	game.addChildAt(bgLayer1, 0);
	game.addChildAt(bgLayer2, 1);
	// Start the animation loop
	animateGradientBackground();
}
function animateGradientBackground() {
	// Pick next color indices
	var nextIdx1 = (bgColorIdx1 + 1) % bgGradientColors.length;
	var nextIdx2 = (bgColorIdx2 + 1) % bgGradientColors.length;
	// Animate tints and alpha for both layers, smoothly transitioning to next color
	tween(bgLayer1, {
		tint: bgGradientColors[nextIdx1],
		alpha: 0.32
	}, {
		duration: bgTweenDuration,
		easing: tween.easeInOut,
		onFinish: function onFinish() {
			bgColorIdx1 = nextIdx1;
			animateGradientBackground();
		}
	});
	tween(bgLayer2, {
		tint: bgGradientColors[nextIdx2],
		alpha: 0.22
	}, {
		duration: bgTweenDuration,
		easing: tween.easeInOut,
		onFinish: function onFinish() {
			bgColorIdx2 = nextIdx2;
		}
	});
}
// Call setupGradientBackground once at game start
setupGradientBackground();
var BALL_SIZE = 420;
var NOTE_WIDTH = 180; // was 120, now wider for less thin look
var NOTE_HEIGHT = 180; // reduced from 260 to make notes less long
var CROSS_SIZE = 160;
var BULLET_SIZE = 60;
var NOTE_COLS = 5;
var NOTE_MARGIN = 60;
var NOTE_AREA_W = GAME_W - 2 * NOTE_MARGIN;
var NOTE_COL_W = NOTE_AREA_W / NOTE_COLS;
var NOTE_START_Y = -NOTE_HEIGHT;
var BALL_X = 180;
var BALL_Y = GAME_H - 220;
var CROSS_MIN_X = 200;
var CROSS_MAX_X = GAME_W - 200;
var CROSS_MIN_Y = 200;
var CROSS_MAX_Y = GAME_H - 400;
var BULLET_SPEED = 48; // px per frame
// --- Game State ---
var notes = [];
var bullets = [];
var crosshair = null;
var ball = null;
var scoreTxt = null;
var tipTxt = null;
var lastNoteSpawnTick = 0;
var noteFallSpeed = 12; // will be set by difficulty
var noteSpawnInterval = 60; // ticks between notes, will be set by difficulty
var difficulty = null; // 'slow', 'normal', 'fast'
var gameStarted = false;
var canShoot = true;
var lastScore = 0;
var musicTracks = [{
	id: 'music1',
	name: 'Parça 1'
}, {
	id: 'music2',
	name: 'Parça 2'
}, {
	id: 'music3',
	name: 'Parça 3'
}];
var currentMusic = null;
// --- Difficulty Presets ---
// Slowed down for all modes
var DIFFICULTY_PRESETS = {
	'slow': {
		noteFallSpeed: 5,
		noteSpawnInterval: 120
	},
	'normal': {
		noteFallSpeed: 7,
		noteSpawnInterval: 90
	},
	'fast': {
		noteFallSpeed: 10,
		noteSpawnInterval: 60
	}
};
// --- UI: Difficulty Selection ---
var diffBtns = [];
function showDifficultyMenu() {
	// Hide facekit video feed if visible
	if (facekit && typeof facekit.setVisible === "function") {
		facekit.setVisible(false);
	}
	// Add Backr image as background
	if (!game._diffMenuBackr) {
		var backr = LK.getAsset('Backr', {
			anchorX: 0.5,
			anchorY: 0.5,
			width: GAME_W,
			height: GAME_H,
			x: GAME_W / 2,
			y: GAME_H / 2,
			scaleMode: 'nearest' // prevent blurriness by using nearest neighbor scaling
		});
		if (typeof backr.setScaleMode === "function") {
			backr.setScaleMode('nearest');
		}
		game.addChild(backr);
		game._diffMenuBackr = backr;
	}
	var btnLabels = [{
		key: 'slow',
		label: 'Slow'
	}, {
		key: 'normal',
		label: 'Normal'
	}, {
		key: 'fast',
		label: 'Fast'
	}];
	var btnW = 500,
		btnH = 180,
		btnGap = 60;
	var startY = GAME_H / 2 - (btnLabels.length * btnH + (btnLabels.length - 1) * btnGap) / 2;
	for (var i = 0; i < btnLabels.length; i++) {
		var btn = new Container();
		var bg = btn.attachAsset('btnbg', {
			anchorX: 0.5,
			anchorY: 0.5,
			width: btnW,
			height: btnH,
			color: 0x222a38,
			shape: 'box'
		});
		var txt = new Text2(btnLabels[i].label, {
			size: 90,
			fill: "#fff"
		});
		txt.anchor.set(0.5, 0.5);
		txt.x = 0;
		txt.y = 0;
		btn.addChild(txt);
		btn.x = GAME_W / 2;
		btn.y = startY + i * (btnH + btnGap);
		btn.difficulty = btnLabels[i].key;
		btn.down = function (x, y, obj) {
			startGame(this.difficulty);
		};
		game.addChild(btn);
		diffBtns.push(btn);
	}
	// Show tip
	if (!tipTxt) {
		tipTxt = new Text2("AIM AT THE NOTES BY\nMOVING YOUR HEAD\nAND FIRE THE GUN BY\nTAPPING THE SCREEN.", {
			size: 70,
			fill: 0xFFFFFF
		});
		tipTxt.anchor.set(0.5, 0);
	}
	// Place btnbg behind tipTxt, sized to match tipTxt
	if (!game._tipBg) {
		// Use tipTxt.width/height after anchor set
		var bgPadX = 60;
		var bgPadY = 40;
		var btnbgW = tipTxt.width + bgPadX;
		var btnbgH = tipTxt.height + bgPadY;
		var tipBg = LK.getAsset('btnbg', {
			anchorX: 0.5,
			anchorY: 0,
			width: btnbgW,
			height: btnbgH,
			color: 0x000000,
			shape: 'box'
		});
		tipBg.x = GAME_W / 2;
		tipBg.y = 180 - bgPadY / 2;
		game.addChild(tipBg);
		game._tipBg = tipBg;
	}
	tipTxt.x = GAME_W / 2;
	tipTxt.y = 180;
	game.addChild(tipTxt);
}
// Remove difficulty menu
function hideDifficultyMenu() {
	// Restore facekit video feed
	if (facekit && typeof facekit.setVisible === "function") {
		facekit.setVisible(true);
	}
	// Remove Backr background if present
	if (game._diffMenuBackr) {
		game._diffMenuBackr.destroy();
		game._diffMenuBackr = null;
	}
	for (var i = 0; i < diffBtns.length; i++) {
		diffBtns[i].destroy();
	}
	diffBtns = [];
	if (tipTxt) {
		tipTxt.destroy();
		tipTxt = null;
		if (game._tipBg) {
			game._tipBg.destroy();
			game._tipBg = null;
		}
	}
}
// --- Start Game ---
function startGame(diffKey) {
	difficulty = diffKey;
	noteFallSpeed = DIFFICULTY_PRESETS[diffKey].noteFallSpeed;
	noteSpawnInterval = DIFFICULTY_PRESETS[diffKey].noteSpawnInterval;
	gameStarted = false; // Will be set to true after countdown
	// Stop menu music if playing
	LK.stopMusic();
	hideDifficultyMenu();
	LK.setScore(0);
	lastScore = 0;
	// Clean up any existing notes and bullets before starting
	for (var i = 0; i < notes.length; i++) {
		if (notes[i]) notes[i].destroy();
	}
	notes = [];
	for (var i = 0; i < bullets.length; i++) {
		if (bullets[i]) bullets[i].destroy();
	}
	bullets = [];
	// Play PH6 only in fast mode, and make it more dominant in randomization
	var musicChoices;
	if (difficulty === 'fast') {
		// PH6 is more dominant: add it multiple times to increase its chance
		musicChoices = ['Ph6', 'Ph6', 'Ph6', 'Piano1', 'P2', 'P3', 'P4', 'P5'];
	} else {
		musicChoices = ['Piano1', 'P2', 'P3', 'P4', 'P5'];
	}
	var selectedMusic = musicChoices[Math.floor(Math.random() * musicChoices.length)];
	// Stop any currently playing music before starting new one
	LK.stopMusic();
	// Play the selected music with default options (looping, full volume)
	LK.playMusic(selectedMusic, {
		loop: true,
		fade: {
			start: 0,
			end: 1,
			duration: 400
		}
	});
	// Ball
	ball = new Ball();
	ball.x = BALL_X;
	ball.y = BALL_Y;
	game.addChild(ball);
	// Crosshair
	crosshair = new Crosshair();
	crosshair.x = BALL_X + 400;
	crosshair.y = BALL_Y - 400;
	game.addChild(crosshair);
	// Score
	if (!scoreTxt) {
		scoreTxt = new Text2('0', {
			size: 120,
			fill: "#fff"
		});
		scoreTxt.anchor.set(0.5, 0);
		LK.gui.top.addChild(scoreTxt);
	}
	scoreTxt.setText(0);
	// Remove tipTxt immediately if present when game starts
	if (tipTxt) {
		tipTxt.destroy();
		tipTxt = null;
	}
	// --- 3 2 1 Go! Countdown ---
	var countdownColors = ["#ff2d2d", "#ffe066", "#7cff66", "#a259ff"];
	var countdownTexts = ["3", "2", "1", "Go!"];
	var countdownObjs = [];
	var countdownIdx = 0;
	function showCountdownStep(idx) {
		// Remove previous countdown text if any
		for (var i = 0; i < countdownObjs.length; i++) {
			if (countdownObjs[i]) {
				countdownObjs[i].destroy();
			}
		}
		countdownObjs = [];
		if (idx < countdownTexts.length) {
			var txt = new Text2(countdownTexts[idx], {
				size: idx === 3 ? 180 : 160,
				fill: countdownColors[idx]
			});
			txt.anchor.set(0.5, 0.5);
			txt.x = GAME_W / 2;
			txt.y = GAME_H / 2;
			game.addChild(txt);
			countdownObjs.push(txt);
			// Animate scale up and fade out
			txt.scale.set(1, 1);
			txt.alpha = 1;
			tween(txt, {
				scaleX: 1.25,
				scaleY: 1.25,
				alpha: 0.0
			}, {
				duration: 600,
				delay: 400,
				onFinish: function onFinish() {
					txt.destroy();
				}
			});
			// Next step after 800ms
			LK.setTimeout(function () {
				showCountdownStep(idx + 1);
			}, 800);
		} else {
			// Countdown finished, start game
			gameStarted = true;
		}
	}
	showCountdownStep(0);
}
// --- End Game ---
function endGame(win) {
	// Clean up
	for (var i = 0; i < notes.length; i++) {
		if (notes[i]) notes[i].destroy();
	}
	notes = [];
	for (var i = 0; i < bullets.length; i++) {
		if (bullets[i]) bullets[i].destroy();
	}
	bullets = [];
	if (ball) {
		ball.destroy();
		ball = null;
	}
	if (crosshair) {
		crosshair.destroy();
		crosshair = null;
	}
	gameStarted = false;
	LK.stopMusic();
	// Play menu music again when returning to menu
	LK.playMusic('Menu1', {
		loop: true
	});
	if (win) {
		LK.showYouWin();
	} else {
		LK.stopMusic();
		LK.showGameOver();
	}
}
// --- Note Spawning ---
function spawnNote() {
	var note = new Note();
	// Pick a random column, now including the far left (index 0) so notes can fall above the gun
	// allowedCols now includes 0,1,2,3,4 (all columns)
	var allowedCols = [];
	for (var i = 0; i < NOTE_COLS; i++) {
		allowedCols.push(i);
	}
	// Increase position variation: allow some random offset within each column
	var col = allowedCols[Math.floor(Math.random() * allowedCols.length)];
	note.column = col;
	// Add random offset within the column for more variation
	var colOffset = 0;
	if (difficulty === 'slow') {
		colOffset = (Math.random() - 0.5) * (NOTE_COL_W * 0.3); // up to ±15% of col width
	} else if (difficulty === 'normal') {
		colOffset = (Math.random() - 0.5) * (NOTE_COL_W * 0.5); // up to ±25% of col width
	} else if (difficulty === 'fast') {
		colOffset = (Math.random() - 0.5) * (NOTE_COL_W * 0.7); // up to ±35% of col width
	}
	note.x = NOTE_MARGIN + NOTE_COL_W / 2 + col * NOTE_COL_W + colOffset;
	note.y = NOTE_START_Y;
	// Increase falling speed slightly per mode
	if (difficulty === 'slow') {
		note.speed = noteFallSpeed + 1.2 + Math.random() * 0.8; // 1.2-2.0 px/frame more
	} else if (difficulty === 'normal') {
		note.speed = noteFallSpeed + 2.2 + Math.random() * 1.2; // 2.2-3.4 px/frame more
	} else if (difficulty === 'fast') {
		note.speed = noteFallSpeed + 3.2 + Math.random() * 1.8; // 3.2-5 px/frame more
	} else {
		note.speed = noteFallSpeed;
	}
	notes.push(note);
	game.addChild(note);
}
// --- Difficulty Increase ---
function maybeIncreaseDifficulty() {
	var score = LK.getScore();
	if (score > 0 && score % 10 === 0 && score !== lastScore) {
		// Increase speed and spawn rate
		noteFallSpeed += 2;
		if (noteSpawnInterval > 20) noteSpawnInterval -= 6;
		lastScore = score;
	}
}
// --- Facekit Crosshair Update ---
function updateCrosshair() {
	if (!crosshair) return;
	// Use facekit.noseTip or facekit.mouthCenter for aiming
	var fx = facekit.noseTip ? facekit.noseTip.x : facekit.mouthCenter ? facekit.mouthCenter.x : GAME_W / 2;
	var fy = facekit.noseTip ? facekit.noseTip.y : facekit.mouthCenter ? facekit.mouthCenter.y : GAME_H / 2;
	// Clamp to play area
	if (fx < CROSS_MIN_X) fx = CROSS_MIN_X;
	if (fx > CROSS_MAX_X) fx = CROSS_MAX_X;
	if (fy < CROSS_MIN_Y) fy = CROSS_MIN_Y;
	if (fy > CROSS_MAX_Y) fy = CROSS_MAX_Y;
	// Instantly set crosshair position (no smoothing, no tween)
	crosshair.x = fx;
	crosshair.y = fy;
}
// --- Fire Bullet ---
function fireBullet() {
	if (!canShoot || !gameStarted) return;
	canShoot = false;
	// Find if crosshair is over a note
	var hitNote = null;
	for (var i = 0; i < notes.length; i++) {
		var n = notes[i];
		if (!n.hit && crosshair && crosshair.intersects(n)) {
			hitNote = n;
			break;
		}
	}
	// Fire bullet towards crosshair
	var b = new Bullet();
	b.x = ball.x;
	b.y = ball.y;
	// Direction vector
	var dx = crosshair.x - ball.x;
	var dy = crosshair.y - ball.y;
	var len = Math.sqrt(dx * dx + dy * dy);
	if (len === 0) {
		dx = 0;
		dy = -1;
		len = 1;
	}
	b.vx = BULLET_SPEED * dx / len;
	b.vy = BULLET_SPEED * dy / len;
	bullets.push(b);
	game.addChild(b);
	// If hitNote, mark as hit (so only one bullet per note)
	if (hitNote) {
		hitNote.hit = true;
	}
	// Play note sound (simulate: play a sound per note column)
	var soundId = 'note' + (hitNote ? hitNote.column : Math.floor(Math.random() * NOTE_COLS));
	LK.getSound(soundId).play();
	// Allow next shot after a normal delay (normal fire rate)
	LK.setTimeout(function () {
		canShoot = true;
	}, 320);
}
// --- Main Game Loop ---
game.down = function (x, y, obj) {
	if (gameStarted) {
		fireBullet();
	}
};
game.update = function () {
	if (!gameStarted) return;
	// --- Optimize: Use local variables, avoid per-frame allocations, and minimize nested loops ---
	// Update crosshair position from facekit
	updateCrosshair();
	// Spawn notes
	if (LK.ticks - lastNoteSpawnTick >= noteSpawnInterval) {
		spawnNote();
		lastNoteSpawnTick = LK.ticks;
	}
	// --- Update notes ---
	// Use a single pass to update and remove notes that are offscreen or hit
	for (var i = notes.length - 1; i >= 0; i--) {
		var n = notes[i];
		n.update();
		// If note falls below screen, only trigger game over if there are still unhit notes
		if (n.y > GAME_H + NOTE_HEIGHT / 2) {
			var anyUnhit = false;
			// Only check for unhit notes if this one is offscreen
			for (var k = 0; k < notes.length; k++) {
				if (!notes[k].hit && notes[k].visible !== false) {
					anyUnhit = true;
					break;
				}
			}
			if (anyUnhit) {
				endGame(false);
				return;
			} else {
				n.visible = false;
				n.destroy();
				notes.splice(i, 1);
				continue;
			}
		}
	}
	// --- Update bullets ---
	// Use local references to avoid repeated property lookups
	for (var i = bullets.length - 1; i >= 0; i--) {
		var b = bullets[i];
		b.update();
		// Remove bullet if out of bounds
		if (b.x < -100 || b.x > GAME_W + 100 || b.y < -100 || b.y > GAME_H + 100) {
			b.destroy();
			bullets.splice(i, 1);
			continue;
		}
		// --- Optimize: Only check for collisions with visible, unhit notes ---
		var bulletHit = false;
		for (var j = notes.length - 1; j >= 0; j--) {
			var n = notes[j];
			if (n.hit || n.visible === false) continue;
			// Initialize lastWasIntersecting if not set
			if (typeof b.lastWasIntersecting === "undefined") b.lastWasIntersecting = false;
			var isIntersecting = b.intersects(n);
			// Make hitbox more forgiving: allow hit if bullet is close to note center (within 0.6*NOTE_WIDTH and 0.6*NOTE_HEIGHT)
			var forgivingHit = false;
			var dx = Math.abs(b.x - n.x);
			var dy = Math.abs(b.y - n.y);
			if (dx < NOTE_WIDTH * 0.6 && dy < NOTE_HEIGHT * 0.6) {
				forgivingHit = true;
			}
			// Only allow hit if note is not already hit and not already destroyed, and bullet just started intersecting or is within forgiving hitbox
			if (b.lastWasIntersecting === false && isIntersecting || forgivingHit) {
				n.hit = true; // Mark as hit immediately to prevent double hits
				LK.setScore(LK.getScore() + 1);
				scoreTxt.setText(LK.getScore());
				// Animate note color to gray/black, then remove
				if (n.children && n.children.length > 0 && n.children[0]) {
					var noteAsset = n.children[0];
					tween(noteAsset, {
						tint: 0x222222
					}, {
						duration: 60,
						onFinish: function (noteAsset, n) {
							return function () {
								if (noteAsset && noteAsset.parent) {
									noteAsset.parent.removeChild(noteAsset);
								}
								n.visible = false;
								n.destroy();
							};
						}(noteAsset, n)
					});
				} else {
					n.visible = false;
					n.destroy();
				}
				// Spawn floating music note effect at note position
				var effect = new MusicNoteEffect();
				effect.start(n.x, n.y);
				game.addChild(effect);
				notes.splice(j, 1);
				b.destroy();
				bullets.splice(i, 1);
				// Difficulty up
				maybeIncreaseDifficulty();
				// Win condition: 50 points
				if (LK.getScore() >= 50) {
					endGame(true);
					return;
				}
				bulletHit = true;
				break;
			}
			b.lastWasIntersecting = isIntersecting;
		}
		if (bulletHit) continue;
	}
};
// --- Show Difficulty Menu on Start ---
// Play menu music when menu is shown
LK.playMusic('Menu1', {
	loop: true
});
showDifficultyMenu();
// Prevent in-game sounds from playing in the menu by disabling their playback when not in game
// Patch LK.getSound to return a dummy object with a no-op play() if not gameStarted
var _LK_getSound = LK.getSound;
LK.getSound = function (id) {
	if (!gameStarted) {
		return {
			play: function play() {}
		};
	}
	return _LK_getSound.call(LK, id);
};
/**** 
* Asset Initialization (for static analysis)
****/ 
// Notes (5 columns, 5 colors)
for (var i = 0; i < NOTE_COLS; i++) {}
// Ball
// Crosshair
// Bullet
// Button background
// Music tracks

===================================================================
--- original.js
+++ change.js
@@ -333,13 +333,32 @@
 	// Show tip
 	if (!tipTxt) {
 		tipTxt = new Text2("AIM AT THE NOTES BY\nMOVING YOUR HEAD\nAND FIRE THE GUN BY\nTAPPING THE SCREEN.", {
 			size: 70,
-			fill: 0xFFFFFF,
-			fontWeight: 700
+			fill: 0xFFFFFF
 		});
 		tipTxt.anchor.set(0.5, 0);
 	}
+	// Place btnbg behind tipTxt, sized to match tipTxt
+	if (!game._tipBg) {
+		// Use tipTxt.width/height after anchor set
+		var bgPadX = 60;
+		var bgPadY = 40;
+		var btnbgW = tipTxt.width + bgPadX;
+		var btnbgH = tipTxt.height + bgPadY;
+		var tipBg = LK.getAsset('btnbg', {
+			anchorX: 0.5,
+			anchorY: 0,
+			width: btnbgW,
+			height: btnbgH,
+			color: 0x000000,
+			shape: 'box'
+		});
+		tipBg.x = GAME_W / 2;
+		tipBg.y = 180 - bgPadY / 2;
+		game.addChild(tipBg);
+		game._tipBg = tipBg;
+	}
 	tipTxt.x = GAME_W / 2;
 	tipTxt.y = 180;
 	game.addChild(tipTxt);
 }
@@ -360,8 +379,12 @@
 	diffBtns = [];
 	if (tipTxt) {
 		tipTxt.destroy();
 		tipTxt = null;
+		if (game._tipBg) {
+			game._tipBg.destroy();
+			game._tipBg = null;
+		}
 	}
 }
 // --- Start Game ---
 function startGame(diffKey) {