/**** 
* Classes
****/
// Background class for the game
var Background = Container.expand(function () {
	var self = Container.call(this);
	var backgroundGraphics = self.createAsset('background_image', 'Background image for the game', 0, 0);
	// Set the background to cover the entire game area
	backgroundGraphics.width = game.width;
	backgroundGraphics.height = game.height;
});
// Marshmallow character class
var Character = Container.expand(function () {
	var self = Container.call(this);
	var characterGraphics = self.createAsset('marshmallow_clipart', 'Fluffy marshmallow character clipart', 0.5, 1);
	self.velocity = {
		x: 0,
		y: 0
	};
	self.isJumping = false;
	self.jump = function () {
		if (!self.isJumping) {
			self.velocity.y = -15;
			self.isJumping = true;
		}
	};
	self.update = function () {
		self.y += self.velocity.y;
		self.velocity.y += 0.5; // gravity effect
		if (self.y > game.height - characterGraphics.height) {
			self.y = game.height - characterGraphics.height;
			self.isJumping = false;
		}
	};
});
// Trap class for obstacles
var Trap = Container.expand(function () {
	var self = Container.call(this);
	var trapGraphics = self.createAsset('trap_clipart', 'Tasty trap obstacle clipart', 0.5, 1);
	self.speed = 5;
	self.move = function () {
		self.x -= self.speed;
	};
	self.isOffScreen = function () {
		return self.x < -trapGraphics.width;
	};
});

/**** 
* Initialize Game
****/
var game = new LK.Game({
	backgroundColor: 0xFFFFFF // Init game with white background
});

/**** 
* Game Code
****/
var background = game.addChild(new Background());
var character = game.addChild(new Character());
character.x = game.width / 4;
character.y = game.height - 100;
var traps = [];
var scoreTxt = new Text2('0', {
	size: 150,
	fill: "#000000"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
game.on('down', function (obj) {
	character.jump();
});
var spawnTrap = function spawnTrap() {
	var trap = new Trap();
	trap.x = game.width;
	trap.y = game.height - 50;
	traps.push(trap);
	game.addChild(trap);
};
var updateScore = function updateScore() {
	LK.setScore(LK.getScore() + 1);
	scoreTxt.setText(LK.getScore());
};
var gameOver = function gameOver() {
	LK.effects.flashScreen(0xff0000, 1000);
	LK.showGameOver();
};
LK.on('tick', function () {
	character.update();
	for (var i = traps.length - 1; i >= 0; i--) {
		traps[i].move();
		if (traps[i].isOffScreen()) {
			traps[i].destroy();
			traps.splice(i, 1);
		} else if (character.intersects(traps[i])) {
			gameOver();
		}
	}
	if (LK.ticks % 120 == 0) {
		spawnTrap();
	}
	if (LK.ticks % 60 == 0) {
		updateScore();
	}
});

===================================================================
--- original.js
+++ change.js
@@ -1,7 +1,15 @@
 /**** 
 * Classes
 ****/
+// Background class for the game
+var Background = Container.expand(function () {
+	var self = Container.call(this);
+	var backgroundGraphics = self.createAsset('background_image', 'Background image for the game', 0, 0);
+	// Set the background to cover the entire game area
+	backgroundGraphics.width = game.width;
+	backgroundGraphics.height = game.height;
+});
 // Marshmallow character class
 var Character = Container.expand(function () {
 	var self = Container.call(this);
 	var characterGraphics = self.createAsset('marshmallow_clipart', 'Fluffy marshmallow character clipart', 0.5, 1);
@@ -47,8 +55,9 @@
 
 /**** 
 * Game Code
 ****/
+var background = game.addChild(new Background());
 var character = game.addChild(new Character());
 character.x = game.width / 4;
 character.y = game.height - 100;
 var traps = [];