var SmallObstacleBox = Container.expand(function () {
	var self = Container.call(this);
	var boxGraphics = self.createAsset('smallObstacleBox', 'Small Obstacle Box', 0.5, 0.5);
	self.x = boxGraphics.width / 2;
	self.y = boxGraphics.height / 2;
});
var MediumObstacleBox = Container.expand(function () {
	var self = Container.call(this);
	var boxGraphics = self.createAsset('mediumObstacleBox', 'Medium Obstacle Box', 0.5, 0.5);
	self.x = boxGraphics.width / 2;
	self.y = boxGraphics.height / 2;
});
var LargeObstacleBox = Container.expand(function () {
	var self = Container.call(this);
	var boxGraphics = self.createAsset('largeObstacleBox', 'Large Obstacle Box', 0.5, 0.5);
	self.x = boxGraphics.width / 2;
	self.y = boxGraphics.height / 2;
});
var Heart = Container.expand(function () {
	var self = Container.call(this);
	var heartGraphics = self.createAsset('heart', 'Player life', 0.5, 0.5);
	self.x = heartGraphics.width / 2;
	self.y = heartGraphics.height / 2;
});
var MuzzleFlash = Container.expand(function () {
	var self = Container.call(this);
	self.visible = false;
	var flashGraphics = self.createAsset('muzzleFlash', 'Muzzle flash effect', .5, .5);
	self.show = function () {
		self.visible = true;
		LK.setTimeout(function () {
			self.visible = false;
		}, 100);
	};
});
var Santa = Container.expand(function () {
	var self = Container.call(this);
	self.santaGraphics = self.createAsset('santa', 'Santa character', .5, .5);
	self.move = function () {};
	self.shoot = function () {};
});
var Crosshair = Container.expand(function () {
	var self = Container.call(this);
	self.move = function (event) {
		var pos = event.getLocalPosition(self.parent);
		self.x = pos.x;
		self.y = pos.y;
	};
	var crosshairGraphics = self.createAsset('crosshair', 'Crosshair', .5, .5);
	self.y = -crosshairGraphics.height / 2;
	self.destroy = function () {};
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	var obstaclePositions = [{
		x: 2048 / 4,
		y: 2732 / 4
	}, {
		x: 2048 / 2,
		y: 2732 / 2
	}, {
		x: 2048 / 4 * 3 - 200,
		y: 2732 / 4 * 3
	}];
	stage.on('move', function (obj) {
		crosshair.move(obj.event);
	});
	stage.on('down', function (obj) {
		muzzleFlash.show();
		leftClickPressed = true;
		lastClickTime = LK.ticks;
		if (!barnMovedDown) {
			barnBackground.y += 460;
			barnMovedDown = true;
		}
	});
	var room1Background = self.createAsset('Room1', 'Room1 background', 0, 0);
	room1Background.anchor.set(0.5, 0.5);
	room1Background.x = 2048 / 2;
	room1Background.y = 2732 / 2;
	self.addChild(room1Background);
	var barnBackground = self.createAsset('Barn', 'Barn background', 0, 0);
	barnBackground.anchor.set(0.5, 0.5);
	barnBackground.x = 2048 / 2;
	barnBackground.y = 2732 - barnBackground.height / 4 + 900;
	self.addChild(barnBackground);
	var santa = new Santa();
	santa.x = 2048 - santa.santaGraphics.width / 2;
	santa.y = 2732 - santa.santaGraphics.height / 2;
	self.addChild(santa);
	var muzzleFlash = new MuzzleFlash();
	muzzleFlash.x = santa.x - santa.santaGraphics.width + 400;
	muzzleFlash.y = santa.y - 90;
	self.addChild(muzzleFlash);
	self.addChild(santa);
	var crosshair = self.addChild(new Crosshair());
	crosshair.x = 2048 / 2;
	crosshair.y = 2732 / 2;
	var isGameOver = false;
	var tickOffset = 0;
	var leftClickPressed = false;
	var barnMovedDown = false;
	var lastClickTime = 0;
	var playerLives = 3;
	var hearts = [];
	for (var i = 0; i < playerLives; i++) {
		var heart = new Heart();
		heart.x = 1150 + i * (heart.width + 1);
		heart.y = santa.y - santa.santaGraphics.height - heart.height / 2 + 350;
		hearts.push(heart);
		LK.gui.topLeft.addChild(heart);
	}
	LK.on('tick', function () {
		santa.move();
		if (isGameOver) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
		}
		obstaclePositions.forEach(function (pos, index) {
			var obstacleBox;
			switch (index) {
				case 0:
					obstacleBox = new SmallObstacleBox();
					break;
				case 1:
					obstacleBox = new MediumObstacleBox();
					break;
				case 2:
					obstacleBox = new LargeObstacleBox();
					break;
			}
			obstacleBox.x = pos.x;
			obstacleBox.y = pos.y;
			self.addChild(obstacleBox);
		});
		if (leftClickPressed && LK.ticks - lastClickTime > 30) {
			barnBackground.y -= 460;
			leftClickPressed = false;
			barnMovedDown = false;
		}
		for (var a = crosshair.length - 1; a >= 0; a--) {
			crosshair[a].move();
			if (crosshair[a].y < -50) {
				crosshair[a].destroy();
				crosshair.splice(a, 1);
			}
		}
	});
});

===================================================================
--- original.js
+++ change.js
@@ -134,9 +134,8 @@
 			self.addChild(obstacleBox);
 		});
 		if (leftClickPressed && LK.ticks - lastClickTime > 30) {
 			barnBackground.y -= 460;
-			room1Background.y -= 100;
 			leftClickPressed = false;
 			barnMovedDown = false;
 		}
 		for (var a = crosshair.length - 1; a >= 0; a--) {