===================================================================
--- original.js
+++ change.js
@@ -1,74 +1,78 @@
-/****
+/**** 
 * Classes
-****/
+****/ 
 // Enemy class
 var Enemy = Container.expand(function () {
-  var self = Container.call(this);
-  var enemyGraphics = self.attachAsset('enemy', {
-    anchorX: 0.5,
-    anchorY: 0.5
-  });
-  self.speed = 5;
-  self.update = function () {
-    self.y += self.speed;
-    if (self.y > 2732) {
-      self.destroy();
-    }
-  };
+	var self = Container.call(this);
+	var enemyGraphics = self.attachAsset('enemy', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = 5;
+	self.update = function () {
+		self.y += self.speed;
+		if (self.y > 2732) {
+			self.destroy();
+		}
+	};
 });
 //<Assets used in the game will automatically appear here>
 //<Write imports for supported plugins here>
 // Hero class
 var Hero = Container.expand(function () {
-  var self = Container.call(this);
-  var heroGraphics = self.attachAsset('hero', {
-    anchorX: 0.5,
-    anchorY: 0.5
-  });
-  self.speed = 10;
-  self.shoot = function () {
-    var bullet = new HeroBullet();
-    bullet.x = self.x;
-    bullet.y = self.y - heroGraphics.height / 2;
-    game.addChild(bullet);
-    heroBullets.push(bullet);
-  };
+	var self = Container.call(this);
+	var heroGraphics = self.attachAsset('hero', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = 10;
+	self.shoot = function () {
+		var bullet = new HeroBullet();
+		bullet.x = self.x;
+		bullet.y = self.y - heroGraphics.height / 2;
+		game.addChild(bullet);
+		heroBullets.push(bullet);
+	};
 });
 // HeroBullet class
 var HeroBullet = Container.expand(function () {
-  var self = Container.call(this);
-  var bulletGraphics = self.attachAsset('heroBullet', {
-    anchorX: 0.5,
-    anchorY: 0.5
-  });
-  self.speed = -15;
-  self.update = function () {
-    self.y += self.speed;
-    if (self.y < 0) {
-      self.destroy();
-    }
-  };
+	var self = Container.call(this);
+	var bulletGraphics = self.attachAsset('heroBullet', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.speed = -15;
+	self.update = function () {
+		self.y += self.speed;
+		if (self.y < 0) {
+			self.destroy();
+		}
+	};
 });
 
-/****
+/**** 
 * Initialize Game
-****/
+****/ 
 var game = new LK.Game({
-  backgroundColor: 0x000000 //Init game with black background 
+	backgroundColor: 0x000000 //Init game with black background
 });
 
-/****
+/**** 
 * Game Code
-****/
+****/ 
+var background = game.attachAsset('background', {
+	anchorX: 0.0,
+	anchorY: 0.0
+});
 // Initialize variables
 var hero;
 var enemies = [];
 var heroBullets = [];
 var score = 0;
 var scoreTxt = new Text2('0', {
-  size: 150,
-  fill: 0xFFFFFF
+	size: 150,
+	fill: 0xFFFFFF
 });
 scoreTxt.anchor.set(0.5, 0);
 LK.gui.top.addChild(scoreTxt);
 // Create hero
@@ -76,48 +80,48 @@
 hero.x = 2048 / 2;
 hero.y = 2732 - 200;
 // Handle game events
 game.down = function (x, y, obj) {
-  hero.x = x;
-  hero.y = y;
+	hero.x = x;
+	hero.y = y;
 };
 game.move = function (x, y, obj) {
-  hero.x = x;
-  hero.y = y;
+	hero.x = x;
+	hero.y = y;
 };
 game.update = function () {
-  // Update hero bullets
-  for (var i = heroBullets.length - 1; i >= 0; i--) {
-    heroBullets[i].update();
-    for (var j = enemies.length - 1; j >= 0; j--) {
-      if (heroBullets[i].intersects(enemies[j])) {
-        enemies[j].destroy();
-        heroBullets[i].destroy();
-        enemies.splice(j, 1);
-        heroBullets.splice(i, 1);
-        score++;
-        scoreTxt.setText(score);
-        break;
-      }
-    }
-  }
-  // Update enemies
-  for (var k = enemies.length - 1; k >= 0; k--) {
-    enemies[k].update();
-    if (enemies[k].intersects(hero)) {
-      LK.effects.flashScreen(0xff0000, 1000);
-      LK.showGameOver();
-    }
-  }
-  // Spawn enemies
-  if (LK.ticks % 60 == 0) {
-    var enemy = new Enemy();
-    enemy.x = Math.random() * 2048;
-    enemy.y = -50;
-    game.addChild(enemy);
-    enemies.push(enemy);
-  }
-  // Hero shooting
-  if (LK.ticks % 15 == 0) {
-    hero.shoot();
-  }
+	// Update hero bullets
+	for (var i = heroBullets.length - 1; i >= 0; i--) {
+		heroBullets[i].update();
+		for (var j = enemies.length - 1; j >= 0; j--) {
+			if (heroBullets[i].intersects(enemies[j])) {
+				enemies[j].destroy();
+				heroBullets[i].destroy();
+				enemies.splice(j, 1);
+				heroBullets.splice(i, 1);
+				score++;
+				scoreTxt.setText(score);
+				break;
+			}
+		}
+	}
+	// Update enemies
+	for (var k = enemies.length - 1; k >= 0; k--) {
+		enemies[k].update();
+		if (enemies[k].intersects(hero)) {
+			LK.effects.flashScreen(0xff0000, 1000);
+			LK.showGameOver();
+		}
+	}
+	// Spawn enemies
+	if (LK.ticks % 60 == 0) {
+		var enemy = new Enemy();
+		enemy.x = Math.random() * 2048;
+		enemy.y = -50;
+		game.addChild(enemy);
+		enemies.push(enemy);
+	}
+	// Hero shooting
+	if (LK.ticks % 15 == 0) {
+		hero.shoot();
+	}
 };
\ No newline at end of file