/**** 
* Classes
****/ 
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -12;
	self.damage = 1;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var Cloud = Container.expand(function () {
	var self = Container.call(this);
	var cloudType = ['cloud1', 'cloud2', 'cloud3'][Math.floor(Math.random() * 3)];
	var cloudGraphics = self.attachAsset(cloudType, {
		anchorX: 0.5,
		anchorY: 0.5
	});
	cloudGraphics.alpha = 0.7;
	self.speed = Math.random() * 2 + 1;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
// Game variables
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	var enemyGraphics = self.attachAsset('enemy', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 3;
	self.health = 1;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var Player = Container.expand(function () {
	var self = Container.call(this);
	var playerGraphics = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 8;
	self.health = 3;
	self.update = function () {
		// Keep player in bounds
		if (self.x < 40) self.x = 40;
		if (self.x > 2008) self.x = 2008;
		if (self.y < 100) self.y = 100;
		if (self.y > 2632) self.y = 2632;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x87CEEB
});

/**** 
* Game Code
****/ 
// Game variables
var player;
var enemies = [];
var bullets = [];
var clouds = [];
var score = 0;
var enemySpawnTimer = 0;
var cloudSpawnTimer = 0;
// Initialize background clouds
for (var i = 0; i < 8; i++) {
	var cloud = new Cloud();
	cloud.x = Math.random() * 2048;
	cloud.y = Math.random() * 2732;
	clouds.push(cloud);
	game.addChild(cloud);
}
// Create player
player = game.addChild(new Player());
player.x = 1024;
player.y = 2400;
// Score display
var scoreTxt = new Text2('Score: ' + score, {
	size: 60,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0, 0);
LK.gui.topLeft.addChild(scoreTxt);
scoreTxt.x = 120;
scoreTxt.y = 20;
// Input handling
game.move = function (x, y, obj) {
	player.x = x;
	player.y = y;
};
game.down = function (x, y, obj) {
	player.x = x;
	player.y = y;
};
// Main game loop
game.update = function () {
	// Spawn new clouds
	cloudSpawnTimer++;
	if (cloudSpawnTimer > 120) {
		var cloud = new Cloud();
		cloud.x = Math.random() * 2048;
		cloud.y = -100;
		clouds.push(cloud);
		game.addChild(cloud);
		cloudSpawnTimer = 0;
	}
	// Update clouds
	for (var i = clouds.length - 1; i >= 0; i--) {
		var cloud = clouds[i];
		if (cloud.y > 2800) {
			cloud.destroy();
			clouds.splice(i, 1);
		}
	}
	// Continuous shooting every 10 ticks
	if (LK.ticks % 10 === 0) {
		var bullet = new Bullet();
		bullet.x = player.x;
		bullet.y = player.y - 60;
		bullets.push(bullet);
		game.addChild(bullet);
		LK.getSound('shoot').play();
	}
	// Spawn enemies
	enemySpawnTimer++;
	if (enemySpawnTimer > 60) {
		var enemy = new Enemy();
		enemy.x = Math.random() * 1900 + 100;
		enemy.y = -50;
		enemies.push(enemy);
		game.addChild(enemy);
		enemySpawnTimer = 0;
	}
	// Update bullets
	for (var i = bullets.length - 1; i >= 0; i--) {
		var bullet = bullets[i];
		// Remove bullets that are off screen
		if (bullet.y < -50) {
			bullet.destroy();
			bullets.splice(i, 1);
			continue;
		}
		// Check bullet-enemy collisions
		for (var j = enemies.length - 1; j >= 0; j--) {
			var enemy = enemies[j];
			if (bullet.intersects(enemy)) {
				// Destroy enemy and bullet
				LK.getSound('explosion').play();
				bullet.destroy();
				bullets.splice(i, 1);
				enemy.destroy();
				enemies.splice(j, 1);
				// Update score
				score += 10;
				LK.setScore(score);
				scoreTxt.setText('Score: ' + score);
				break;
			}
		}
	}
	// Update enemies
	for (var i = enemies.length - 1; i >= 0; i--) {
		var enemy = enemies[i];
		// Remove enemies that are off screen
		if (enemy.y > 2800) {
			enemy.destroy();
			enemies.splice(i, 1);
			continue;
		}
		// Check enemy-player collision
		if (enemy.intersects(player)) {
			player.health--;
			if (player.health <= 0) {
				LK.showGameOver();
			} else {
				LK.effects.flashObject(player, 0xff0000, 500);
			}
			enemy.destroy();
			enemies.splice(i, 1);
		}
	}
};

===================================================================
--- original.js
+++ change.js
@@ -13,8 +13,22 @@
 		self.y += self.speed;
 	};
 	return self;
 });
+var Cloud = Container.expand(function () {
+	var self = Container.call(this);
+	var cloudType = ['cloud1', 'cloud2', 'cloud3'][Math.floor(Math.random() * 3)];
+	var cloudGraphics = self.attachAsset(cloudType, {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	cloudGraphics.alpha = 0.7;
+	self.speed = Math.random() * 2 + 1;
+	self.update = function () {
+		self.y += self.speed;
+	};
+	return self;
+});
 // Game variables
 var Enemy = Container.expand(function () {
 	var self = Container.call(this);
 	var enemyGraphics = self.attachAsset('enemy', {
@@ -49,9 +63,9 @@
 /**** 
 * Initialize Game
 ****/ 
 var game = new LK.Game({
-	backgroundColor: 0x000000
+	backgroundColor: 0x87CEEB
 });
 
 /**** 
 * Game Code
@@ -59,10 +73,20 @@
 // Game variables
 var player;
 var enemies = [];
 var bullets = [];
+var clouds = [];
 var score = 0;
 var enemySpawnTimer = 0;
+var cloudSpawnTimer = 0;
+// Initialize background clouds
+for (var i = 0; i < 8; i++) {
+	var cloud = new Cloud();
+	cloud.x = Math.random() * 2048;
+	cloud.y = Math.random() * 2732;
+	clouds.push(cloud);
+	game.addChild(cloud);
+}
 // Create player
 player = game.addChild(new Player());
 player.x = 1024;
 player.y = 2400;
@@ -85,8 +109,26 @@
 	player.y = y;
 };
 // Main game loop
 game.update = function () {
+	// Spawn new clouds
+	cloudSpawnTimer++;
+	if (cloudSpawnTimer > 120) {
+		var cloud = new Cloud();
+		cloud.x = Math.random() * 2048;
+		cloud.y = -100;
+		clouds.push(cloud);
+		game.addChild(cloud);
+		cloudSpawnTimer = 0;
+	}
+	// Update clouds
+	for (var i = clouds.length - 1; i >= 0; i--) {
+		var cloud = clouds[i];
+		if (cloud.y > 2800) {
+			cloud.destroy();
+			clouds.splice(i, 1);
+		}
+	}
 	// Continuous shooting every 10 ticks
 	if (LK.ticks % 10 === 0) {
 		var bullet = new Bullet();
 		bullet.x = player.x;