var Opponent = Container.expand(function () {
	var self = Container.call(this);
	var opponentGraphics = self.createAsset('opponent', 'Opponent Graphics', .5, .5);
	opponentGraphics.scale.set(-3, 3);
	self.speed = 3;
	self.hitPoints = 3;
	self.move = function (heroX, heroY) {
		var dx = heroX - self.x;
		var dy = heroY - self.y;
		var distance = Math.sqrt(dx * dx + dy * dy);
		self.x += self.speed * (dx / distance);
		self.y += self.speed * (dy / distance);
	};
	self.hit = function (punchX, punchY) {
		self.hitPoints--;
		var dx = self.x - punchX;
		var dy = self.y - punchY;
		var distance = Math.sqrt(dx * dx + dy * dy);
		self.x += 100 * (dx / distance);
		self.y += 100 * (dy / distance);
		if (self.hitPoints <= 0) {
			self.destroy();
		}
	};
});
var Hero = Container.expand(function () {
	var self = Container.call(this);
	var heroGraphics = self.createAsset('hero', 'Hero character', .5, .5);
	heroGraphics.scale.set(6);
	self.speed = 5;
	self.move = function () {};
	self.punch = function () {};
});
var Punch = Container.expand(function () {
	var self = Container.call(this);
	self.velocity = {
		x: 0,
		y: 0
	};
	self.setVelocity = function (targetX, targetY) {
		var dx = targetX - self.x;
		var dy = targetY - self.y;
		var distance = Math.sqrt(dx * dx + dy * dy);
		self.velocity.x = self.speed * (dx / distance);
		self.velocity.y = self.speed * (dy / distance);
	};
	self.move = function () {
		self.x += self.velocity.x;
		self.y += self.velocity.y;
	};
	var punchGraphics = self.createAsset('punch', 'Punch Graphics', .5, .5);
	punchGraphics.scale.set(2);
	punchGraphics.rotation = Math.PI / 2;
	self.speed = 15;
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	var background = self.createAsset('boxingRing', 'Boxing Ring Background', 0, 0);
	background.scale.set(LK.stage.width / background.width, LK.stage.height / background.height);
	self.addChildAt(background, 0);
	var hero = self.addChild(new Hero());
	var enemies = [];
	var punches = [];
	var opponents = [];
	var opponentSpawnRate = 120;
	var opponentSpawnCounter = 0;
	var scoreTxt = new Text2('0', {
		size: 150,
		fill: "#ffffff"
	});
	LK.gui.topCenter.addChild(scoreTxt);
	var isGameOver = false;
	var tickOffset = 0;
	var glovesKillsCount = 0;
	var speedIncreaseTimer = 0;
	var speedIncreaseInterval = 300;
	var speedMultiplier = 1;
	hero.x = hero.width / 2;
	hero.y = 2732 / 2;
	var punchCooldown = 500;
	var lastPunchTime = 0;
	LK.stage.on('down', function (obj) {
		var currentTime = Date.now();
		if (currentTime - lastPunchTime >= punchCooldown) {
			var event = obj.event;
			var tapPosition = event.getLocalPosition(self);
			var punch = new Punch();
			punch.x = hero.x;
			punch.y = hero.y;
			punch.setVelocity(tapPosition.x, tapPosition.y);
			punches.push(punch);
			self.addChild(punch);
			LK.effects.flashObject(hero, 0xffcc00, 100);
			lastPunchTime = currentTime;
		}
	});
	LK.on('tick', function () {
		hero.move();
		for (var i = punches.length - 1; i >= 0; i--) {
			var punch = punches[i];
			punch.move();
			for (var j = opponents.length - 1; j >= 0; j--) {
				var opponent = opponents[j];
				if (punch.intersects(opponent)) {
					opponent.hit(punch.x, punch.y);
					if (opponent.hitPoints <= 0) {
						glovesKillsCount++;
						scoreTxt.setText(glovesKillsCount.toString());
						opponents.splice(j, 1);
					}
					punch.destroy();
					punches.splice(i, 1);
					break;
				}
			}
		}
		speedIncreaseTimer++;
		if (speedIncreaseTimer >= speedIncreaseInterval) {
			speedMultiplier += 0.2;
			Opponent.prototype.speed *= speedMultiplier;
			Punch.prototype.speed *= speedMultiplier;
			speedIncreaseTimer = 0;
			var fasterText = new Text2('FASTER!', {
				size: 200,
				fill: '#ff0000',
				align: 'center'
			});
			fasterText.x = LK.stage.width / 2 - 100;
			fasterText.y = LK.stage.height / 2 - 100;
			fasterText.anchor.set(0.5, 0.5);
			LK.gui.addChild(fasterText);
			LK.setTimeout(function () {
				fasterText.destroy();
			}, 1000);
		}
		if (opponentSpawnCounter++ >= opponentSpawnRate) {
			var opponent = new Opponent();
			opponent.x = LK.stage.width;
			opponent.y = Math.random() * (LK.stage.height - opponent.height) + opponent.height / 2;
			opponents.push(opponent);
			self.addChild(opponent);
			opponentSpawnCounter = 0;
		}
		for (var j = opponents.length - 1; j >= 0; j--) {
			var opponent = opponents[j];
			opponent.move(hero.x, hero.y);
			if (opponent.intersects(hero)) {
				isGameOver = true;
			}
			if (opponent.x + opponent.width / 2 < 0) {
				opponent.destroy();
				opponents.splice(j, 1);
			}
		}
		if (isGameOver) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
		}
	});
});

===================================================================
--- original.js
+++ change.js
@@ -40,10 +40,10 @@
 	self.setVelocity = function (targetX, targetY) {
 		var dx = targetX - self.x;
 		var dy = targetY - self.y;
 		var distance = Math.sqrt(dx * dx + dy * dy);
-		self.velocity.x = Punch.prototype.speed * (dx / distance);
-		self.velocity.y = Punch.prototype.speed * (dy / distance);
+		self.velocity.x = self.speed * (dx / distance);
+		self.velocity.y = self.speed * (dy / distance);
 	};
 	self.move = function () {
 		self.x += self.velocity.x;
 		self.y += self.velocity.y;
@@ -124,10 +124,10 @@
 				size: 200,
 				fill: '#ff0000',
 				align: 'center'
 			});
-			fasterText.x = LK.stage.width / 2;
-			fasterText.y = LK.stage.height / 2;
+			fasterText.x = LK.stage.width / 2 - 100;
+			fasterText.y = LK.stage.height / 2 - 100;
 			fasterText.anchor.set(0.5, 0.5);
 			LK.gui.addChild(fasterText);
 			LK.setTimeout(function () {
 				fasterText.destroy();