===================================================================
--- original.js
+++ change.js
@@ -1,6 +1,94 @@
-/****
+/**** 
+* Classes
+****/ 
+var Bullet = Container.expand(function (startX, startY) {
+	var self = Container.call(this);
+	var bulletGraphics = self.attachAsset('bullet', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.x = startX;
+	self.y = startY;
+	self.speed = -10;
+	self.update = function () {
+		self.y += self.speed;
+		if (self.y < 0) {
+			self.destroy();
+		}
+	};
+});
+var Enemy = Container.expand(function () {
+	var self = Container.call(this);
+	var enemyGraphics = self.attachAsset('enemy', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = 2;
+	self.update = function () {
+		self.y += self.speed;
+		if (self.y > 2732) {
+			self.y = 0;
+			self.x = Math.random() * 2048;
+		}
+	};
+});
+var Player = Container.expand(function () {
+	var self = Container.call(this);
+	var playerGraphics = self.attachAsset('player', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = 5;
+	self.shoot = function () {
+		var bullet = new Bullet(self.x, self.y - 50);
+		game.addChild(bullet);
+		bullets.push(bullet);
+		LK.getSound('shoot').play();
+	};
+	self.update = function () {
+		// Player movement logic
+		if (self.x > 0) {
+			self.x -= self.speed;
+		}
+		if (self.x < 2048) {
+			self.x += self.speed;
+		}
+	};
+});
+
+/**** 
 * Initialize Game
-****/
+****/ 
 var game = new LK.Game({
 	backgroundColor: 0x000000 // Initialize game with black background
-});
\ No newline at end of file
+});
+
+/**** 
+* Game Code
+****/ 
+// Initialize assets used in this game.
+var player = new Player();
+game.addChild(player);
+player.x = 1024;
+player.y = 2500;
+var enemies = [];
+for (var i = 0; i < 5; i++) {
+	var enemy = new Enemy();
+	enemy.x = Math.random() * 2048;
+	enemy.y = Math.random() * 1000;
+	game.addChild(enemy);
+	enemies.push(enemy);
+}
+var bullets = [];
+game.update = function () {
+	player.update();
+	enemies.forEach(function (enemy) {
+		enemy.update();
+	});
+	bullets.forEach(function (bullet, index) {
+		bullet.update();
+		if (bullet.y < 0) {
+			bullets.splice(index, 1);
+		}
+	});
+};
\ No newline at end of file