var Nutcracker = Container.expand(function () {
	var self = Container.call(this);
	var nutcrackerGraphics = self.createAsset('nutcracker', 'Nutcracker Graphics', .5, .5);
	self.move = function () {};
	self.attack = function () {};
});
var MouseTrap = Container.expand(function () {
	var self = Container.call(this);
	var mousetrapGraphics = self.createAsset('mousetrap', 'Mouse Trap Graphics', .5, .5);
	self.activate = function () {};
});
var Mouse = Container.expand(function () {
	var self = Container.call(this);
	var mouseGraphics = self.createAsset('mouse', 'Mouse Graphics', .5, .5);
	self.move = function () {};
	self.attack = function () {};
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	var background = self.createAsset('background', 'Background Graphics', 0, 0);
	self.addChildAt(background, 0);
	var nutcrackers = [];
	var mousetraps = [];
	var mice = [];
	var initGame = function () {
		for (var i = 0; i < 5; i++) {
			var nutcracker = new Nutcracker();
			nutcracker.x = Math.random() * 2048;
			nutcracker.y = Math.random() * 2732;
			nutcrackers.push(nutcracker);
			self.addChild(nutcracker);
		}
		for (var i = 0; i < 5; i++) {
			var mousetrap = new MouseTrap();
			mousetrap.x = Math.random() * 2048;
			mousetrap.y = Math.random() * 2732;
			mousetraps.push(mousetrap);
			self.addChild(mousetrap);
		}
		for (var i = 0; i < 10; i++) {
			var mouse = new Mouse();
			mouse.x = Math.random() * 2048;
			mouse.y = Math.random() * 2732;
			mice.push(mouse);
			self.addChild(mouse);
		}
	};
	LK.on('tick', function () {
		for (var i = 0; i < nutcrackers.length; i++) {
			nutcrackers[i].move();
			nutcrackers[i].attack();
		}
		for (var i = 0; i < mousetraps.length; i++) {
			mousetraps[i].activate();
		}
		for (var i = 0; i < mice.length; i++) {
			mice[i].move();
			mice[i].attack();
		}
	});
	initGame();
});

===================================================================
--- original.js
+++ change.js
@@ -16,8 +16,10 @@
 	self.attack = function () {};
 });
 var Game = Container.expand(function () {
 	var self = Container.call(this);
+	var background = self.createAsset('background', 'Background Graphics', 0, 0);
+	self.addChildAt(background, 0);
 	var nutcrackers = [];
 	var mousetraps = [];
 	var mice = [];
 	var initGame = function () {