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

/**** 
* Classes
****/ 
var BackgroundStar = Container.expand(function () {
	var self = Container.call(this);
	var starGraphics = self.attachAsset('star_bg', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -1; // Very slow parallax
	self.twinkleTimer = Math.random() * 100;
	self.update = function () {
		self.x += self.speed;
		self.twinkleTimer++;
		starGraphics.alpha = 0.3 + Math.sin(self.twinkleTimer * 0.05) * 0.7;
	};
	return self;
});
var Building = Container.expand(function () {
	var self = Container.call(this);
	var buildingType = Math.floor(Math.random() * 3) + 1;
	var buildingGraphics = self.attachAsset('building' + buildingType, {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.speed = -2; // Slower parallax speed
	// Add windows randomly
	for (var i = 0; i < 6; i++) {
		if (Math.random() > 0.4) {
			var window = self.attachAsset('window', {
				anchorX: 0.5,
				anchorY: 0.5
			});
			window.x = (Math.random() - 0.5) * buildingGraphics.width * 0.6;
			window.y = -Math.random() * buildingGraphics.height * 0.8;
		}
	}
	self.update = function () {
		self.x += self.speed;
	};
	return self;
});
var Coin = Container.expand(function () {
	var self = Container.call(this);
	var coinGraphics = self.attachAsset('coin', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -8;
	self.value = 10;
	self.bobOffset = 0;
	self.update = function () {
		self.x += self.speed;
		// Add bobbing animation
		self.bobOffset += 0.1;
		coinGraphics.y = Math.sin(self.bobOffset) * 10;
	};
	return self;
});
var Player = Container.expand(function () {
	var self = Container.call(this);
	var playerGraphics = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.velocityY = 0;
	self.isJumping = false;
	self.jumpForce = -35;
	self.gravity = 1.2;
	self.groundY = 2532; // Ground level
	self.update = function () {
		// Apply gravity
		self.velocityY += self.gravity;
		self.y += self.velocityY;
		// Check ground collision
		if (self.y >= self.groundY) {
			self.y = self.groundY;
			self.velocityY = 0;
			self.isJumping = false;
		}
	};
	self.jump = function () {
		if (!self.isJumping) {
			self.velocityY = self.jumpForce;
			self.isJumping = true;
			LK.getSound('jump').play();
		}
	};
	return self;
});
var Star = Container.expand(function () {
	var self = Container.call(this);
	var starGraphics = self.attachAsset('star', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -8;
	self.value = 50;
	self.rotationSpeed = 0.1;
	self.update = function () {
		self.x += self.speed;
		starGraphics.rotation += self.rotationSpeed;
	};
	return self;
});
var Turtle = Container.expand(function () {
	var self = Container.call(this);
	var turtleGraphics = self.attachAsset('turtle', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.speed = -8;
	self.groundY = 2532;
	self.update = function () {
		self.x += self.speed;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x1a1a2e
});

/**** 
* Game Code
****/ 
// Game variables
var gameSpeed = 8;
var spawnTimer = 0;
var difficultyTimer = 0;
var distance = 0;
var scoreMultiplier = 1;
// Game objects
var player;
var ground;
var moon;
var turtles = [];
var coins = [];
var stars = [];
var buildings = [];
var backgroundStars = [];
// UI elements
var scoreTxt = new Text2('0', {
	size: 100,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
var distanceTxt = new Text2('0m', {
	size: 80,
	fill: 0xFFFFFF
});
distanceTxt.anchor.set(1, 0);
LK.gui.topRight.addChild(distanceTxt);
// Initialize game elements
function initializeGame() {
	// Create moon
	moon = game.addChild(LK.getAsset('moon', {
		anchorX: 0.5,
		anchorY: 0.5
	}));
	moon.x = 1700;
	moon.y = 400;
	// Create background stars
	for (var i = 0; i < 15; i++) {
		var bgStar = new BackgroundStar();
		bgStar.x = Math.random() * 2500;
		bgStar.y = Math.random() * 800 + 200;
		backgroundStars.push(bgStar);
		game.addChild(bgStar);
	}
	// Create initial buildings
	for (var i = 0; i < 12; i++) {
		var building = new Building();
		building.x = i * 200 + Math.random() * 100;
		building.y = 2732;
		buildings.push(building);
		game.addChild(building);
	}
	// Create ground
	ground = game.addChild(LK.getAsset('ground', {
		anchorX: 0,
		anchorY: 1
	}));
	ground.x = 0;
	ground.y = 2732;
	// Create player
	player = game.addChild(new Player());
	player.x = 300;
	player.y = 2532;
	// Start background music
	LK.playMusic('bgmusic');
}
// Spawn turtle enemy
function spawnTurtle() {
	var turtle = new Turtle();
	turtle.x = 2200;
	turtle.y = 2532;
	turtle.speed = -(gameSpeed + Math.random() * 4);
	turtles.push(turtle);
	game.addChild(turtle);
}
// Spawn coin
function spawnCoin() {
	var coin = new Coin();
	coin.x = 2200;
	coin.y = 2400 - Math.random() * 300;
	coin.speed = -gameSpeed;
	coins.push(coin);
	game.addChild(coin);
}
// Spawn star
function spawnStar() {
	var star = new Star();
	star.x = 2200;
	star.y = 2300 - Math.random() * 200;
	star.speed = -gameSpeed;
	stars.push(star);
	game.addChild(star);
}
// Spawn building
function spawnBuilding() {
	var building = new Building();
	building.x = 2200;
	building.y = 2732;
	buildings.push(building);
	game.addChild(building);
}
// Touch controls
game.down = function (x, y, obj) {
	player.jump();
};
// Main game loop
game.update = function () {
	// Update distance
	distance += gameSpeed / 10;
	distanceTxt.setText(Math.floor(distance) + 'm');
	// Increase difficulty over time
	difficultyTimer++;
	if (difficultyTimer % 1800 === 0) {
		// Every 30 seconds
		gameSpeed += 0.5;
	}
	// Spawn enemies and collectibles
	spawnTimer++;
	// Spawn turtles
	if (spawnTimer % 120 === 0) {
		spawnTurtle();
	}
	// Spawn coins
	if (spawnTimer % 180 === 0) {
		spawnCoin();
	}
	// Spawn stars (less frequent)
	if (spawnTimer % 480 === 0) {
		spawnStar();
	}
	// Spawn buildings for background
	if (spawnTimer % 300 === 0) {
		spawnBuilding();
	}
	// Update and check turtles
	for (var i = turtles.length - 1; i >= 0; i--) {
		var turtle = turtles[i];
		// Remove if off screen
		if (turtle.x < -100) {
			turtle.destroy();
			turtles.splice(i, 1);
			continue;
		}
		// Check collision with player
		if (turtle.intersects(player)) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
			return;
		}
	}
	// Update and check coins
	for (var i = coins.length - 1; i >= 0; i--) {
		var coin = coins[i];
		// Remove if off screen
		if (coin.x < -100) {
			coin.destroy();
			coins.splice(i, 1);
			continue;
		}
		// Check collection
		if (coin.intersects(player)) {
			LK.setScore(LK.getScore() + coin.value * scoreMultiplier);
			scoreTxt.setText(LK.getScore());
			LK.getSound('coin').play();
			coin.destroy();
			coins.splice(i, 1);
		}
	}
	// Update and check stars
	for (var i = stars.length - 1; i >= 0; i--) {
		var star = stars[i];
		// Remove if off screen
		if (star.x < -100) {
			star.destroy();
			stars.splice(i, 1);
			continue;
		}
		// Check collection
		if (star.intersects(player)) {
			LK.setScore(LK.getScore() + star.value * scoreMultiplier);
			scoreTxt.setText(LK.getScore());
			scoreMultiplier += 0.1;
			LK.getSound('star').play();
			LK.effects.flashObject(star, 0xFFFFFF, 500);
			star.destroy();
			stars.splice(i, 1);
		}
	}
	// Update and cleanup buildings
	for (var i = buildings.length - 1; i >= 0; i--) {
		var building = buildings[i];
		if (building.x < -300) {
			building.destroy();
			buildings.splice(i, 1);
		}
	}
	// Update and cleanup background stars
	for (var i = backgroundStars.length - 1; i >= 0; i--) {
		var bgStar = backgroundStars[i];
		if (bgStar.x < -50) {
			bgStar.destroy();
			backgroundStars.splice(i, 1);
			// Spawn new star
			var newStar = new BackgroundStar();
			newStar.x = 2100 + Math.random() * 200;
			newStar.y = Math.random() * 800 + 200;
			backgroundStars.push(newStar);
			game.addChild(newStar);
		}
	}
	// Add distance to score
	LK.setScore(LK.getScore() + Math.floor(gameSpeed / 10));
	scoreTxt.setText(LK.getScore());
};
// Initialize the game
initializeGame();

===================================================================
--- original.js
+++ change.js
@@ -5,8 +5,47 @@
 
 /**** 
 * Classes
 ****/ 
+var BackgroundStar = Container.expand(function () {
+	var self = Container.call(this);
+	var starGraphics = self.attachAsset('star_bg', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = -1; // Very slow parallax
+	self.twinkleTimer = Math.random() * 100;
+	self.update = function () {
+		self.x += self.speed;
+		self.twinkleTimer++;
+		starGraphics.alpha = 0.3 + Math.sin(self.twinkleTimer * 0.05) * 0.7;
+	};
+	return self;
+});
+var Building = Container.expand(function () {
+	var self = Container.call(this);
+	var buildingType = Math.floor(Math.random() * 3) + 1;
+	var buildingGraphics = self.attachAsset('building' + buildingType, {
+		anchorX: 0.5,
+		anchorY: 1.0
+	});
+	self.speed = -2; // Slower parallax speed
+	// Add windows randomly
+	for (var i = 0; i < 6; i++) {
+		if (Math.random() > 0.4) {
+			var window = self.attachAsset('window', {
+				anchorX: 0.5,
+				anchorY: 0.5
+			});
+			window.x = (Math.random() - 0.5) * buildingGraphics.width * 0.6;
+			window.y = -Math.random() * buildingGraphics.height * 0.8;
+		}
+	}
+	self.update = function () {
+		self.x += self.speed;
+	};
+	return self;
+});
 var Coin = Container.expand(function () {
 	var self = Container.call(this);
 	var coinGraphics = self.attachAsset('coin', {
 		anchorX: 0.5,
@@ -86,9 +125,9 @@
 /**** 
 * Initialize Game
 ****/ 
 var game = new LK.Game({
-	backgroundColor: 0x87CEEB
+	backgroundColor: 0x1a1a2e
 });
 
 /**** 
 * Game Code
@@ -101,11 +140,14 @@
 var scoreMultiplier = 1;
 // Game objects
 var player;
 var ground;
+var moon;
 var turtles = [];
 var coins = [];
 var stars = [];
+var buildings = [];
+var backgroundStars = [];
 // UI elements
 var scoreTxt = new Text2('0', {
 	size: 100,
 	fill: 0xFFFFFF
@@ -119,8 +161,31 @@
 distanceTxt.anchor.set(1, 0);
 LK.gui.topRight.addChild(distanceTxt);
 // Initialize game elements
 function initializeGame() {
+	// Create moon
+	moon = game.addChild(LK.getAsset('moon', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	}));
+	moon.x = 1700;
+	moon.y = 400;
+	// Create background stars
+	for (var i = 0; i < 15; i++) {
+		var bgStar = new BackgroundStar();
+		bgStar.x = Math.random() * 2500;
+		bgStar.y = Math.random() * 800 + 200;
+		backgroundStars.push(bgStar);
+		game.addChild(bgStar);
+	}
+	// Create initial buildings
+	for (var i = 0; i < 12; i++) {
+		var building = new Building();
+		building.x = i * 200 + Math.random() * 100;
+		building.y = 2732;
+		buildings.push(building);
+		game.addChild(building);
+	}
 	// Create ground
 	ground = game.addChild(LK.getAsset('ground', {
 		anchorX: 0,
 		anchorY: 1
@@ -160,8 +225,16 @@
 	star.speed = -gameSpeed;
 	stars.push(star);
 	game.addChild(star);
 }
+// Spawn building
+function spawnBuilding() {
+	var building = new Building();
+	building.x = 2200;
+	building.y = 2732;
+	buildings.push(building);
+	game.addChild(building);
+}
 // Touch controls
 game.down = function (x, y, obj) {
 	player.jump();
 };
@@ -189,8 +262,12 @@
 	// Spawn stars (less frequent)
 	if (spawnTimer % 480 === 0) {
 		spawnStar();
 	}
+	// Spawn buildings for background
+	if (spawnTimer % 300 === 0) {
+		spawnBuilding();
+	}
 	// Update and check turtles
 	for (var i = turtles.length - 1; i >= 0; i--) {
 		var turtle = turtles[i];
 		// Remove if off screen
@@ -243,8 +320,30 @@
 			star.destroy();
 			stars.splice(i, 1);
 		}
 	}
+	// Update and cleanup buildings
+	for (var i = buildings.length - 1; i >= 0; i--) {
+		var building = buildings[i];
+		if (building.x < -300) {
+			building.destroy();
+			buildings.splice(i, 1);
+		}
+	}
+	// Update and cleanup background stars
+	for (var i = backgroundStars.length - 1; i >= 0; i--) {
+		var bgStar = backgroundStars[i];
+		if (bgStar.x < -50) {
+			bgStar.destroy();
+			backgroundStars.splice(i, 1);
+			// Spawn new star
+			var newStar = new BackgroundStar();
+			newStar.x = 2100 + Math.random() * 200;
+			newStar.y = Math.random() * 800 + 200;
+			backgroundStars.push(newStar);
+			game.addChild(newStar);
+		}
+	}
 	// Add distance to score
 	LK.setScore(LK.getScore() + Math.floor(gameSpeed / 10));
 	scoreTxt.setText(LK.getScore());
 };