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

/**** 
* Classes
****/ 
var Ball = Container.expand(function (color, size) {
	var self = Container.call(this);
	self.ballColor = color;
	self.ballSize = size;
	self.velocityX = 0;
	self.velocityY = 0;
	self.gravity = 0.5;
	self.bounce = 0.6;
	self.friction = 0.98;
	self.merged = false;
	var ballAsset;
	if (color === 'green') {
		ballAsset = self.attachAsset('greenBall', {
			anchorX: 0.5,
			anchorY: 0.5
		});
		self.radius = 40;
	} else if (color === 'blue') {
		ballAsset = self.attachAsset('blueBall', {
			anchorX: 0.5,
			anchorY: 0.5
		});
		self.radius = 60;
	} else if (color === 'purple') {
		ballAsset = self.attachAsset('purpleBall', {
			anchorX: 0.5,
			anchorY: 0.5
		});
		self.radius = 80;
	}
	self.update = function () {
		if (self.merged) return;
		// Apply gravity
		self.velocityY += self.gravity;
		// Apply friction
		self.velocityX *= self.friction;
		self.velocityY *= self.friction;
		// Update position
		self.x += self.velocityX;
		self.y += self.velocityY;
		// Floor collision
		if (self.y + self.radius > gameFloor) {
			self.y = gameFloor - self.radius;
			self.velocityY *= -self.bounce;
			if (Math.abs(self.velocityY) < 1) {
				self.velocityY = 0;
			}
		}
		// Wall collisions
		if (self.x - self.radius < gameLeftWall + 20) {
			self.x = gameLeftWall + 20 + self.radius;
			self.velocityX *= -self.bounce;
		}
		if (self.x + self.radius > gameRightWall - 20) {
			self.x = gameRightWall - 20 - self.radius;
			self.velocityX *= -self.bounce;
		}
		// Check for merges with other balls
		for (var i = 0; i < balls.length; i++) {
			var otherBall = balls[i];
			if (otherBall === self || otherBall.merged) continue;
			var dx = self.x - otherBall.x;
			var dy = self.y - otherBall.y;
			var distance = Math.sqrt(dx * dx + dy * dy);
			if (distance < self.radius + otherBall.radius) {
				// Collision detected
				if (self.ballColor === otherBall.ballColor && !self.merging && !otherBall.merging) {
					// Same color - merge
					self.merging = true;
					otherBall.merging = true;
					mergeBalls(self, otherBall);
				} else {
					// Different colors - bounce
					var angle = Math.atan2(dy, dx);
					var sin = Math.sin(angle);
					var cos = Math.cos(angle);
					var vx1 = self.velocityX * cos + self.velocityY * sin;
					var vy1 = self.velocityY * cos - self.velocityX * sin;
					var vx2 = otherBall.velocityX * cos + otherBall.velocityY * sin;
					var vy2 = otherBall.velocityY * cos - otherBall.velocityX * sin;
					var finalVx1 = vx2;
					var finalVx2 = vx1;
					self.velocityX = finalVx1 * cos - vy1 * sin;
					self.velocityY = vy1 * cos + finalVx1 * sin;
					otherBall.velocityX = finalVx2 * cos - vy2 * sin;
					otherBall.velocityY = vy2 * cos + finalVx2 * sin;
					// Separate balls
					var overlap = self.radius + otherBall.radius - distance;
					var moveX = overlap * 0.5 * cos;
					var moveY = overlap * 0.5 * sin;
					self.x += moveX;
					self.y += moveY;
					otherBall.x -= moveX;
					otherBall.y -= moveY;
				}
			}
		}
	};
	return self;
});
var MenuButton = Container.expand(function (assetId, callback) {
	var self = Container.call(this);
	self.buttonAsset = self.attachAsset(assetId, {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.callback = callback;
	self.down = function (x, y, obj) {
		LK.getSound('button').play();
		self.buttonAsset.alpha = 0.7;
		if (self.callback) {
			self.callback();
		}
	};
	self.up = function (x, y, obj) {
		self.buttonAsset.alpha = 1.0;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x222222
});

/**** 
* Game Code
****/ 
// Game state management
var gameState = 'mainMenu'; // 'mainMenu', 'levelSelect', 'gameplay'
var balls = [];
var gameLevel = storage.currentLevel || 1;
var maxUnlockedLevel = storage.maxUnlockedLevel || 1;
var gameScore = 0;
var gameTime = 60000; // 60 seconds
var gameStartTime = Date.now();
var targetScore = gameLevel * 100;
var dropCooldown = 0;
var gameLeftWall = 124;
var gameRightWall = 1924;
var gameFloor = 2500;
var nextBallColor = 'green';
// Menu containers
var mainMenuContainer = new Container();
var levelSelectContainer = new Container();
var gameplayContainer = new Container();
// Initialize main menu
function initMainMenu() {
	mainMenuContainer.removeChildren();
	// Title
	var titleText = new Text2('Color Merge Drop', {
		size: 120,
		fill: 0xFFFFFF
	});
	titleText.anchor.set(0.5, 0.5);
	titleText.x = 1024;
	titleText.y = 800;
	mainMenuContainer.addChild(titleText);
	// Central play button
	var playButton = new MenuButton('menuButton', function () {
		showLevelSelect();
	});
	playButton.x = 1024;
	playButton.y = 1366;
	mainMenuContainer.addChild(playButton);
	game.addChild(mainMenuContainer);
}
// Initialize level select screen
function initLevelSelect() {
	levelSelectContainer.removeChildren();
	// Title
	var titleText = new Text2('Select Level', {
		size: 100,
		fill: 0xFFFFFF
	});
	titleText.anchor.set(0.5, 0.5);
	titleText.x = 1024;
	titleText.y = 400;
	levelSelectContainer.addChild(titleText);
	// Level buttons (3x3 grid)
	var startX = 424;
	var startY = 800;
	var spacing = 400;
	for (var i = 1; i <= 9; i++) {
		var row = Math.floor((i - 1) / 3);
		var col = (i - 1) % 3;
		var x = startX + col * spacing;
		var y = startY + row * spacing;
		var isUnlocked = i <= maxUnlockedLevel;
		var buttonAsset = isUnlocked ? 'levelButton' : 'lockedButton';
		if (isUnlocked) {
			var levelButton = new MenuButton(buttonAsset, function (level) {
				return function () {
					startLevel(level);
				};
			}(i));
			levelButton.x = x;
			levelButton.y = y;
			levelSelectContainer.addChild(levelButton);
			// Level number
			var levelNumText = new Text2(i.toString(), {
				size: 60,
				fill: 0xFFFFFF
			});
			levelNumText.anchor.set(0.5, 0.5);
			levelNumText.x = x;
			levelNumText.y = y;
			levelSelectContainer.addChild(levelNumText);
		} else {
			var lockedButton = levelSelectContainer.addChild(LK.getAsset(buttonAsset, {
				anchorX: 0.5,
				anchorY: 0.5
			}));
			lockedButton.x = x;
			lockedButton.y = y;
		}
	}
	// Back button
	var backButton = new MenuButton('backButton', function () {
		showMainMenu();
	});
	backButton.x = 200;
	backButton.y = 2500;
	levelSelectContainer.addChild(backButton);
	var backText = new Text2('Back', {
		size: 40,
		fill: 0xFFFFFF
	});
	backText.anchor.set(0.5, 0.5);
	backText.x = 200;
	backText.y = 2500;
	levelSelectContainer.addChild(backText);
}
// Initialize gameplay elements
function initGameplay() {
	gameplayContainer.removeChildren();
	// Create game boundaries
	var leftWall = gameplayContainer.addChild(LK.getAsset('wall', {
		anchorX: 0,
		anchorY: 0
	}));
	leftWall.x = gameLeftWall;
	leftWall.y = 200;
	var rightWall = gameplayContainer.addChild(LK.getAsset('wall', {
		anchorX: 0,
		anchorY: 0
	}));
	rightWall.x = gameRightWall;
	rightWall.y = 200;
	var floor = gameplayContainer.addChild(LK.getAsset('floor', {
		anchorX: 0,
		anchorY: 0
	}));
	floor.x = gameLeftWall + 20;
	floor.y = gameFloor;
	// Create drop zone
	var dropZone = gameplayContainer.addChild(LK.getAsset('dropZone', {
		anchorX: 0.5,
		anchorY: 0
	}));
	dropZone.x = 1024;
	dropZone.y = 100;
	game.addChild(gameplayContainer);
}
// Create UI elements
var scoreText = new Text2('Score: 0', {
	size: 60,
	fill: 0xFFFFFF
});
scoreText.anchor.set(0, 0);
scoreText.x = 150;
scoreText.y = 50;
var timeText = new Text2('Time: 60', {
	size: 60,
	fill: 0xFFFFFF
});
timeText.anchor.set(1, 0);
timeText.x = -50;
timeText.y = 50;
var targetText = new Text2('Target: ' + targetScore, {
	size: 50,
	fill: 0xFFFF00
});
targetText.anchor.set(0, 0);
targetText.x = 150;
targetText.y = 120;
var levelText = new Text2('Level ' + gameLevel, {
	size: 70,
	fill: 0x00FF00
});
levelText.anchor.set(0.5, 0);
levelText.y = 50;
function createBall(x, y, color) {
	var ball = new Ball(color);
	ball.x = x;
	ball.y = y;
	balls.push(ball);
	game.addChild(ball);
	LK.getSound('drop').play();
	return ball;
}
function mergeBalls(ball1, ball2) {
	LK.getSound('merge').play();
	var mergeX = (ball1.x + ball2.x) / 2;
	var mergeY = (ball1.y + ball2.y) / 2;
	// Mark balls as merged
	ball1.merged = true;
	ball2.merged = true;
	// Remove from balls array
	var index1 = balls.indexOf(ball1);
	var index2 = balls.indexOf(ball2);
	if (index1 > -1) balls.splice(index1, 1);
	if (index2 > -1) balls.splice(index2, 1);
	// Remove from display
	ball1.destroy();
	ball2.destroy();
	// Create next color ball or add score
	if (ball1.ballColor === 'green') {
		var newBall = createBall(mergeX, mergeY, 'blue');
		newBall.velocityX = (ball1.velocityX + ball2.velocityX) / 2;
		newBall.velocityY = (ball1.velocityY + ball2.velocityY) / 2;
	} else if (ball1.ballColor === 'blue') {
		var newBall = createBall(mergeX, mergeY, 'purple');
		newBall.velocityX = (ball1.velocityX + ball2.velocityX) / 2;
		newBall.velocityY = (ball1.velocityY + ball2.velocityY) / 2;
	} else if (ball1.ballColor === 'purple') {
		// Purple balls disappear and give score
		gameScore += 50;
		LK.getSound('score').play();
		LK.effects.flashObject(scoreText, 0xffff00, 500);
	}
	updateScore();
}
function updateScore() {
	scoreText.setText('Score: ' + gameScore);
	if (gameScore >= targetScore) {
		// Level complete
		if (gameLevel >= maxUnlockedLevel) {
			maxUnlockedLevel = gameLevel + 1;
			storage.maxUnlockedLevel = maxUnlockedLevel;
		}
		storage.currentLevel = gameLevel + 1;
		LK.showYouWin();
	}
}
function updateTimer() {
	var elapsed = Date.now() - gameStartTime;
	var remaining = Math.max(0, Math.ceil((gameTime - elapsed) / 1000));
	timeText.setText('Time: ' + remaining);
	if (remaining <= 0 && gameScore < targetScore) {
		LK.showGameOver();
	}
}
function showMainMenu() {
	gameState = 'mainMenu';
	game.removeChildren();
	LK.gui.topLeft.removeChildren();
	LK.gui.topRight.removeChildren();
	LK.gui.top.removeChildren();
	initMainMenu();
}
function showLevelSelect() {
	gameState = 'levelSelect';
	game.removeChildren();
	initLevelSelect();
}
function startLevel(level) {
	gameState = 'gameplay';
	gameLevel = level;
	targetScore = gameLevel * 100;
	gameScore = 0;
	gameStartTime = Date.now();
	dropCooldown = 0;
	balls = [];
	game.removeChildren();
	initGameplay();
	// Update UI text
	scoreText.setText('Score: 0');
	timeText.setText('Time: 60');
	targetText.setText('Target: ' + targetScore);
	levelText.setText('Level ' + gameLevel);
	// Add UI to GUI
	LK.gui.topLeft.addChild(scoreText);
	LK.gui.topLeft.addChild(targetText);
	LK.gui.topRight.addChild(timeText);
	LK.gui.top.addChild(levelText);
}
// Touch/click handler
game.down = function (x, y, obj) {
	if (gameState === 'gameplay') {
		if (dropCooldown > 0) return;
		// Drop ball at x position within drop zone
		var dropX = Math.max(gameLeftWall + 60, Math.min(gameRightWall - 60, x));
		createBall(dropX, 200, nextBallColor);
		dropCooldown = 30; // 0.5 second cooldown
	}
};
// Initialize game with main menu
showMainMenu();
game.update = function () {
	if (gameState === 'gameplay') {
		// Update cooldown
		if (dropCooldown > 0) {
			dropCooldown--;
		}
		// Update timer
		updateTimer();
		// Clean up merged balls
		for (var i = balls.length - 1; i >= 0; i--) {
			if (balls[i].merged) {
				balls.splice(i, 1);
			}
		}
		// Check for balls that fell off screen
		for (var i = balls.length - 1; i >= 0; i--) {
			if (balls[i].y > 2732) {
				balls[i].destroy();
				balls.splice(i, 1);
			}
		}
	}
};

===================================================================
--- original.js
+++ change.js
@@ -106,8 +106,27 @@
 		}
 	};
 	return self;
 });
+var MenuButton = Container.expand(function (assetId, callback) {
+	var self = Container.call(this);
+	self.buttonAsset = self.attachAsset(assetId, {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.callback = callback;
+	self.down = function (x, y, obj) {
+		LK.getSound('button').play();
+		self.buttonAsset.alpha = 0.7;
+		if (self.callback) {
+			self.callback();
+		}
+	};
+	self.up = function (x, y, obj) {
+		self.buttonAsset.alpha = 1.0;
+	};
+	return self;
+});
 
 /**** 
 * Initialize Game
 ****/ 
@@ -117,10 +136,13 @@
 
 /**** 
 * Game Code
 ****/ 
+// Game state management
+var gameState = 'mainMenu'; // 'mainMenu', 'levelSelect', 'gameplay'
 var balls = [];
 var gameLevel = storage.currentLevel || 1;
+var maxUnlockedLevel = storage.maxUnlockedLevel || 1;
 var gameScore = 0;
 var gameTime = 60000; // 60 seconds
 var gameStartTime = Date.now();
 var targetScore = gameLevel * 100;
@@ -128,65 +150,157 @@
 var gameLeftWall = 124;
 var gameRightWall = 1924;
 var gameFloor = 2500;
 var nextBallColor = 'green';
-// Create game boundaries
-var leftWall = game.addChild(LK.getAsset('wall', {
-	anchorX: 0,
-	anchorY: 0
-}));
-leftWall.x = gameLeftWall;
-leftWall.y = 200;
-var rightWall = game.addChild(LK.getAsset('wall', {
-	anchorX: 0,
-	anchorY: 0
-}));
-rightWall.x = gameRightWall;
-rightWall.y = 200;
-var floor = game.addChild(LK.getAsset('floor', {
-	anchorX: 0,
-	anchorY: 0
-}));
-floor.x = gameLeftWall + 20;
-floor.y = gameFloor;
-// Create drop zone
-var dropZone = game.addChild(LK.getAsset('dropZone', {
-	anchorX: 0.5,
-	anchorY: 0
-}));
-dropZone.x = 1024;
-dropZone.y = 100;
-// Create UI
+// Menu containers
+var mainMenuContainer = new Container();
+var levelSelectContainer = new Container();
+var gameplayContainer = new Container();
+// Initialize main menu
+function initMainMenu() {
+	mainMenuContainer.removeChildren();
+	// Title
+	var titleText = new Text2('Color Merge Drop', {
+		size: 120,
+		fill: 0xFFFFFF
+	});
+	titleText.anchor.set(0.5, 0.5);
+	titleText.x = 1024;
+	titleText.y = 800;
+	mainMenuContainer.addChild(titleText);
+	// Central play button
+	var playButton = new MenuButton('menuButton', function () {
+		showLevelSelect();
+	});
+	playButton.x = 1024;
+	playButton.y = 1366;
+	mainMenuContainer.addChild(playButton);
+	game.addChild(mainMenuContainer);
+}
+// Initialize level select screen
+function initLevelSelect() {
+	levelSelectContainer.removeChildren();
+	// Title
+	var titleText = new Text2('Select Level', {
+		size: 100,
+		fill: 0xFFFFFF
+	});
+	titleText.anchor.set(0.5, 0.5);
+	titleText.x = 1024;
+	titleText.y = 400;
+	levelSelectContainer.addChild(titleText);
+	// Level buttons (3x3 grid)
+	var startX = 424;
+	var startY = 800;
+	var spacing = 400;
+	for (var i = 1; i <= 9; i++) {
+		var row = Math.floor((i - 1) / 3);
+		var col = (i - 1) % 3;
+		var x = startX + col * spacing;
+		var y = startY + row * spacing;
+		var isUnlocked = i <= maxUnlockedLevel;
+		var buttonAsset = isUnlocked ? 'levelButton' : 'lockedButton';
+		if (isUnlocked) {
+			var levelButton = new MenuButton(buttonAsset, function (level) {
+				return function () {
+					startLevel(level);
+				};
+			}(i));
+			levelButton.x = x;
+			levelButton.y = y;
+			levelSelectContainer.addChild(levelButton);
+			// Level number
+			var levelNumText = new Text2(i.toString(), {
+				size: 60,
+				fill: 0xFFFFFF
+			});
+			levelNumText.anchor.set(0.5, 0.5);
+			levelNumText.x = x;
+			levelNumText.y = y;
+			levelSelectContainer.addChild(levelNumText);
+		} else {
+			var lockedButton = levelSelectContainer.addChild(LK.getAsset(buttonAsset, {
+				anchorX: 0.5,
+				anchorY: 0.5
+			}));
+			lockedButton.x = x;
+			lockedButton.y = y;
+		}
+	}
+	// Back button
+	var backButton = new MenuButton('backButton', function () {
+		showMainMenu();
+	});
+	backButton.x = 200;
+	backButton.y = 2500;
+	levelSelectContainer.addChild(backButton);
+	var backText = new Text2('Back', {
+		size: 40,
+		fill: 0xFFFFFF
+	});
+	backText.anchor.set(0.5, 0.5);
+	backText.x = 200;
+	backText.y = 2500;
+	levelSelectContainer.addChild(backText);
+}
+// Initialize gameplay elements
+function initGameplay() {
+	gameplayContainer.removeChildren();
+	// Create game boundaries
+	var leftWall = gameplayContainer.addChild(LK.getAsset('wall', {
+		anchorX: 0,
+		anchorY: 0
+	}));
+	leftWall.x = gameLeftWall;
+	leftWall.y = 200;
+	var rightWall = gameplayContainer.addChild(LK.getAsset('wall', {
+		anchorX: 0,
+		anchorY: 0
+	}));
+	rightWall.x = gameRightWall;
+	rightWall.y = 200;
+	var floor = gameplayContainer.addChild(LK.getAsset('floor', {
+		anchorX: 0,
+		anchorY: 0
+	}));
+	floor.x = gameLeftWall + 20;
+	floor.y = gameFloor;
+	// Create drop zone
+	var dropZone = gameplayContainer.addChild(LK.getAsset('dropZone', {
+		anchorX: 0.5,
+		anchorY: 0
+	}));
+	dropZone.x = 1024;
+	dropZone.y = 100;
+	game.addChild(gameplayContainer);
+}
+// Create UI elements
 var scoreText = new Text2('Score: 0', {
 	size: 60,
 	fill: 0xFFFFFF
 });
 scoreText.anchor.set(0, 0);
-LK.gui.topLeft.addChild(scoreText);
 scoreText.x = 150;
 scoreText.y = 50;
 var timeText = new Text2('Time: 60', {
 	size: 60,
 	fill: 0xFFFFFF
 });
 timeText.anchor.set(1, 0);
-LK.gui.topRight.addChild(timeText);
 timeText.x = -50;
 timeText.y = 50;
 var targetText = new Text2('Target: ' + targetScore, {
 	size: 50,
 	fill: 0xFFFF00
 });
 targetText.anchor.set(0, 0);
-LK.gui.topLeft.addChild(targetText);
 targetText.x = 150;
 targetText.y = 120;
 var levelText = new Text2('Level ' + gameLevel, {
 	size: 70,
 	fill: 0x00FF00
 });
 levelText.anchor.set(0.5, 0);
-LK.gui.top.addChild(levelText);
 levelText.y = 50;
 function createBall(x, y, color) {
 	var ball = new Ball(color);
 	ball.x = x;
@@ -231,8 +345,12 @@
 function updateScore() {
 	scoreText.setText('Score: ' + gameScore);
 	if (gameScore >= targetScore) {
 		// Level complete
+		if (gameLevel >= maxUnlockedLevel) {
+			maxUnlockedLevel = gameLevel + 1;
+			storage.maxUnlockedLevel = maxUnlockedLevel;
+		}
 		storage.currentLevel = gameLevel + 1;
 		LK.showYouWin();
 	}
 }
@@ -243,33 +361,73 @@
 	if (remaining <= 0 && gameScore < targetScore) {
 		LK.showGameOver();
 	}
 }
+function showMainMenu() {
+	gameState = 'mainMenu';
+	game.removeChildren();
+	LK.gui.topLeft.removeChildren();
+	LK.gui.topRight.removeChildren();
+	LK.gui.top.removeChildren();
+	initMainMenu();
+}
+function showLevelSelect() {
+	gameState = 'levelSelect';
+	game.removeChildren();
+	initLevelSelect();
+}
+function startLevel(level) {
+	gameState = 'gameplay';
+	gameLevel = level;
+	targetScore = gameLevel * 100;
+	gameScore = 0;
+	gameStartTime = Date.now();
+	dropCooldown = 0;
+	balls = [];
+	game.removeChildren();
+	initGameplay();
+	// Update UI text
+	scoreText.setText('Score: 0');
+	timeText.setText('Time: 60');
+	targetText.setText('Target: ' + targetScore);
+	levelText.setText('Level ' + gameLevel);
+	// Add UI to GUI
+	LK.gui.topLeft.addChild(scoreText);
+	LK.gui.topLeft.addChild(targetText);
+	LK.gui.topRight.addChild(timeText);
+	LK.gui.top.addChild(levelText);
+}
 // Touch/click handler
 game.down = function (x, y, obj) {
-	if (dropCooldown > 0) return;
-	// Drop ball at x position within drop zone
-	var dropX = Math.max(gameLeftWall + 60, Math.min(gameRightWall - 60, x));
-	createBall(dropX, 200, nextBallColor);
-	dropCooldown = 30; // 0.5 second cooldown
+	if (gameState === 'gameplay') {
+		if (dropCooldown > 0) return;
+		// Drop ball at x position within drop zone
+		var dropX = Math.max(gameLeftWall + 60, Math.min(gameRightWall - 60, x));
+		createBall(dropX, 200, nextBallColor);
+		dropCooldown = 30; // 0.5 second cooldown
+	}
 };
+// Initialize game with main menu
+showMainMenu();
 game.update = function () {
-	// Update cooldown
-	if (dropCooldown > 0) {
-		dropCooldown--;
-	}
-	// Update timer
-	updateTimer();
-	// Clean up merged balls
-	for (var i = balls.length - 1; i >= 0; i--) {
-		if (balls[i].merged) {
-			balls.splice(i, 1);
+	if (gameState === 'gameplay') {
+		// Update cooldown
+		if (dropCooldown > 0) {
+			dropCooldown--;
 		}
-	}
-	// Check for balls that fell off screen
-	for (var i = balls.length - 1; i >= 0; i--) {
-		if (balls[i].y > 2732) {
-			balls[i].destroy();
-			balls.splice(i, 1);
+		// Update timer
+		updateTimer();
+		// Clean up merged balls
+		for (var i = balls.length - 1; i >= 0; i--) {
+			if (balls[i].merged) {
+				balls.splice(i, 1);
+			}
 		}
+		// Check for balls that fell off screen
+		for (var i = balls.length - 1; i >= 0; i--) {
+			if (balls[i].y > 2732) {
+				balls[i].destroy();
+				balls.splice(i, 1);
+			}
+		}
 	}
 };
\ No newline at end of file