var BloodSplatter = Container.expand(function () {
	var self = Container.call(this);
	var bloodSplatterGraphics = self.createAsset('bloodSplatter', 'Blood Splatter Graphics', .5, .5);
	bloodSplatterGraphics.rotation = Math.random() * 2 * Math.PI;
	self.despawn = function () {
		LK.setTimeout(function () {
			self.destroy();
		}, 3000);
	};
	self.despawn();
});
var Shuriken = Container.expand(function () {
	var self = Container.call(this);
	var shurikenGraphics = self.createAsset('shuriken', 'Shuriken Graphics', .5, .5);
	self.speed = 20;
	self.move = function () {
		;
		self.y -= self.speed;
	};
});
var Rat = Container.expand(function () {
	var self = Container.call(this);
	var ratGraphics = self.createAsset('rat', 'Rat Graphics', .5, .5);
	self.speed = Math.random() * 3 + 1;
	self.move = function () {
		self.y += self.speed;
		if (self.y >= 2732) {
			LK.showGameOver();
		}
	};
});
var PowerUp = Container.expand(function () {
	var self = Container.call(this);
	var powerUpGraphics = self.createAsset('powerUp', 'PowerUp Graphics', .5, .5);
	self.activate = function () {};
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	var background = self.createAsset('wooden_floor', 'Level Background', 0, 0);
	background.width = 2048;
	background.height = 2732;
	background.isCollisionObject = false;
	var scoreTxt = new Text2('0', {
		size: 150,
		fill: "#ffffff"
	});
	scoreTxt.anchor.set(.5, 0);
	LK.gui.topCenter.addChild(scoreTxt);
	var shurikens = [];
	var rats = [];
	var powerUps = [];
	var isGameOver = false;
	var tickOffset = 0;
	var score = 0;
	var ratSpeedIncrease = 0;
	var mouseDownTime = 0;
	function init() {
		spawnRats();
	}
	function spawnRats() {
		var spawnTime = Math.random() * 2000 + 1000;
		LK.setTimeout(function () {
			var rat = new Rat();
			rat.speed += ratSpeedIncrease;
			rat.x = Math.random() * 2048;
			rat.y = 0;
			rats.push(rat);
			self.addChild(rat);
			spawnRats();
		}, spawnTime);
	}
	function update() {}
	function gameOver() {}
	function checkCollision() {
		for (var i = 0; i < shurikens.length; i++) {
			for (var j = 0; j < rats.length; j++) {
				if (shurikens[i].intersects(rats[j])) {
					self.removeChild(shurikens[i]);
					shurikens.splice(i, 1);
					self.removeChild(rats[j]);
					var bloodSplatter = new BloodSplatter();
					bloodSplatter.x = rats[j].x;
					bloodSplatter.y = rats[j].y;
					self.addChild(bloodSplatter);
					bloodSplatter.despawn();
					rats.splice(j, 1);
					score++;
					if (score % 10 === 0) {
						ratSpeedIncrease += 0.1;
					}
					break;
				}
			}
		}
	}
	function updateScore() {
		scoreTxt.setText(score);
	}
	stage.on('down', function (obj) {
		mouseDownTime = LK.ticks;
		var shuriken = new Shuriken();
		shuriken.x = obj.event.getLocalPosition(self).x;
		shuriken.y = 2732;
		shurikens.push(shuriken);
		self.addChild(shuriken);
	});
	stage.on('move', function (obj) {});
	stage.on('up', function (obj) {
		var timeHeld = LK.ticks - mouseDownTime;
		shurikens[shurikens.length - 1].speed = timeHeld / 10;
	});
	LK.on('tick', function () {
		update();
		for (var i = 0; i < rats.length; i++) {
			rats[i].move();
		}
		for (var i = 0; i < shurikens.length; i++) {
			shurikens[i].move();
		}
		checkCollision();
		updateScore();
		if (isGameOver) {
			gameOver();
		}
	});
	init();
});

===================================================================
--- original.js
+++ change.js
@@ -52,8 +52,9 @@
 	var isGameOver = false;
 	var tickOffset = 0;
 	var score = 0;
 	var ratSpeedIncrease = 0;
+	var mouseDownTime = 0;
 	function init() {
 		spawnRats();
 	}
 	function spawnRats() {
@@ -95,16 +96,20 @@
 	function updateScore() {
 		scoreTxt.setText(score);
 	}
 	stage.on('down', function (obj) {
+		mouseDownTime = LK.ticks;
 		var shuriken = new Shuriken();
 		shuriken.x = obj.event.getLocalPosition(self).x;
 		shuriken.y = 2732;
 		shurikens.push(shuriken);
 		self.addChild(shuriken);
 	});
 	stage.on('move', function (obj) {});
-	stage.on('up', function (obj) {});
+	stage.on('up', function (obj) {
+		var timeHeld = LK.ticks - mouseDownTime;
+		shurikens[shurikens.length - 1].speed = timeHeld / 10;
+	});
 	LK.on('tick', function () {
 		update();
 		for (var i = 0; i < rats.length; i++) {
 			rats[i].move();