var Branch = Container.expand(function () {
	var self = Container.call(this);
	var branchGraphics = self.createAsset('branch', 'Branch Graphics', .5, .5);
	self.move = function () {};
	self.update = function () {};
});
var Bird = Container.expand(function () {
	var self = Container.call(this);
	var birdGraphics = self.createAsset('bird', 'Bird Graphics', .5, .5);
	self.move = function () {};
	self.update = function () {};
});
var Monkey = Container.expand(function () {
	var self = Container.call(this);
	var monkeyGraphics = self.createAsset('monkey', 'Monkey Graphics', .5, .5);
	self.vx = 0;
	self.vy = 0;
	self.gravity = 0.5;
	self.jumpingFrom = null;
	self.jump = function (target, branch) {
		if (target) {
			var dx = target.x - self.x;
			var dy = target.y - self.y;
			if (dy > 0) return;
			var distance = Math.sqrt(dx * dx + dy * dy);
			self.vx = dx / distance * 25;
			self.vy = dy / distance * 25;
			self.jumpingFrom = branch;
		}
	};
	self.update = function () {
		self.x = Math.max(0, Math.min(2048 - self.width, self.x + self.vx));
		self.y += self.vy;
		self.vy += self.gravity;
		if (self.vy > 0) {
			self.jumpingFrom = null;
		}
		if (self.y > 2732 - self.height) {
			self.y = 2732 - self.height;
			self.vy = 0;
			self.vx = 0;
		}
	};
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	var branches = [];
	for (var i = 0; i < 20; i++) {
		var newBranch = new Branch();
		newBranch.x = Math.random() * 2048;
		newBranch.y = i * (2732 / 20);
		branches.push(newBranch);
		self.addChild(newBranch);
	}
	for (var i = 0; i < 3; i++) {
		var newBird = new Bird();
		newBird.x = Math.random() * 2048;
		self.addChild(newBird);
		birds.push(newBird);
	}
	var level = 1;
	var levelTxt = new Text2('Level: ' + level, {
		size: 150,
		fill: '#ffffff'
	});
	levelTxt.anchor.set(.5, 0);
	LK.gui.topCenter.addChild(levelTxt);
	var monkey = self.addChild(new Monkey());
	monkey.x = 1024;
	monkey.y = 2732 - monkey.height;
	var birds = [];
	for (var i = 0; i < 3; i++) {
		var newBird = new Bird();
		newBird.x = Math.random() * 2048;
		self.addChild(newBird);
		birds.push(newBird);
	}
	LK.on('tick', function () {
		monkey.update();
		for (var i = 0; i < branches.length; i++) {
			branches[i].update();
			if (branches[i].y > 2732) {
				branches[i].destroy();
				branches.splice(i, 1);
				i--;
			}
		}
		for (var i = 0; i < birds.length; i++) {
			birds[i].update();
			if (birds[i].y > 2732) {
				birds[i].destroy();
				birds.splice(i, 1);
				i--;
			}
		}
		for (var i = 0; i < branches.length; i++) {
			if (branches[i] !== monkey.jumpingFrom && monkey.intersects(branches[i])) {
				monkey.vx = 0;
				monkey.vy = 0;
			}
		}
		if (monkey.y <= branches[0].y) {
			monkey.x = 1024;
			monkey.y = 2732 - monkey.height;
			level++;
			levelTxt.setText('Level: ' + level);
			for (var i = 0; i < branches.length; i++) {
				branches[i].destroy();
			}
			branches = [];
			for (var i = 0; i < 20; i++) {
				var newBranch = new Branch();
				newBranch.x = Math.random() * 2048;
				newBranch.y = i * (2732 / 20);
				branches.push(newBranch);
				self.addChild(newBranch);
			}
		}
		for (var i = 0; i < birds.length; i++) {
			if (monkey.intersects(birds[i])) {
				LK.showGameOver();
			}
		}
	});
	stage.on('down', function (obj) {
		var pos = obj.event.getLocalPosition(self);
		var currentBranch = null;
		for (var i = 0; i < branches.length; i++) {
			if (monkey.intersects(branches[i])) {
				currentBranch = branches[i];
				break;
			}
		}
		monkey.jump({
			x: pos.x,
			y: pos.y
		}, currentBranch);
	});
});

===================================================================
--- original.js
+++ change.js
@@ -68,8 +68,14 @@
 	var monkey = self.addChild(new Monkey());
 	monkey.x = 1024;
 	monkey.y = 2732 - monkey.height;
 	var birds = [];
+	for (var i = 0; i < 3; i++) {
+		var newBird = new Bird();
+		newBird.x = Math.random() * 2048;
+		self.addChild(newBird);
+		birds.push(newBird);
+	}
 	LK.on('tick', function () {
 		monkey.update();
 		for (var i = 0; i < branches.length; i++) {
 			branches[i].update();