var Wall = Container.expand(function () {
	var self = Container.call(this);
	self.createAsset('wall', 'Wall', 0, 0);
	self.isBarrier = true;
});
var HeroBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.createAsset('heroBullet', 'Hero Bullet Graphics', .5, .5);
	self.speed = -10;
	self.move = function () {
		self.x += self.speedX;
		self.y += self.speedY;
	};
	self.timer = LK.setTimeout(function () {
		self.destroy();
	}, 5000);
});
var EnemyBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.createAsset('enemyBullet', 'Enemy Bullet Graphics', .5, .5);
	self.speed = 10;
	self.move = function () {
		self.x += self.speed;
	};
	self.timer = LK.setTimeout(function () {
		self.destroy();
	}, 5000);
});
var Hero = Container.expand(function () {
	var self = Container.call(this);
	self.update = function () {
		if (self.dx && self.dy) {
			self.x -= self.dx;
			self.y -= self.dy;
			self.dx *= 0.95;
			self.dy *= 0.95;
			if (Math.abs(self.dx) < 0.01 && Math.abs(self.dy) < 0.01) {
				self.dx = 0;
				self.dy = 0;
			}
		}
	};
	var heroGraphics = self.createAsset('hero', 'Hero character', .5, .5);
	heroGraphics.rotation = 42 * (Math.PI / 180);
	self.knockback = function (dx, dy) {
		self.dx = -dx * 116.886 * 3.645;
		self.dy = -dy * 116.886 * 3.645;
	};
});
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	self.graphics = self.createAsset('enemy', 'Enemy character', .5, .5);
	self.followHero = function (hero) {
		var dx = hero.x - self.x;
		var dy = hero.y - self.y;
		var mag = Math.sqrt(dx * dx + dy * dy);
		self.x += 3.85 * dx / mag;
		self.y += 3.85 * dy / mag;
	};
});
var Game = Container.expand(function () {
	var self = Container.call(this);
	var enemies = [];
	LK.stageContainer.setBackgroundColor(0x000000);
	self.startingScene = true;
	var startButton = self.createAsset('startButton', 'Start Button', .5, .5);
	startButton.x = 1024;
	startButton.y = 1366;
	var hero;
	startButton.on('down', function () {
		self.removeChild(startButton);
		hero = self.addChild(new Hero());
		var enemies = [];
		startButton.on('down', function () {
			self.removeChild(startButton);
			hero = self.addChild(new Hero());
			var newEnemy = self.addChild(new Enemy());
			enemies.push(newEnemy);
			hero.x = 1024;
			hero.y = 1366;
			self.startingScene = false;
		});
	});
	var leftWall = self.addChild(new Wall());
	leftWall.width = 81.92;
	leftWall.height = 2732;
	leftWall.x = 0;
	leftWall.y = 0;
	var rightWall = self.addChild(new Wall());
	rightWall.width = 81.92;
	rightWall.height = 2732;
	rightWall.x = 2048 - 81.92;
	rightWall.y = 0;
	var topWall = self.addChild(new Wall());
	topWall.width = 2048;
	topWall.height = 109.28;
	topWall.x = 0;
	topWall.y = 0;
	var bottomWall = self.addChild(new Wall());
	bottomWall.width = 2048;
	bottomWall.height = 109.28;
	bottomWall.x = 0;
	bottomWall.y = 2732 - 109.28;
	var heroBullets = [];
	var enemyBullets = [];
	var isGameOver = false;
	var tickOffset = 0;
	var fpsCounter = new Text2('0', {
		size: 50,
		fill: '#ffffff'
	});
	LK.gui.topCenter.addChild(fpsCounter);
	var gameTimerCounter = new Text2('0', {
		size: 50,
		fill: '#ffffff'
	});
	gameTimerCounter.x = -50;
	LK.gui.topRight.addChild(gameTimerCounter);
	var gameStartTime = Date.now();
	var lastTick = Date.now();
	var frameCount = 0;
	LK.on('tick', function () {
		if (self.startingScene) {
			return;
		}
		if (isGameOver) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
		}
		frameCount++;
		var now = Date.now();
		if (now - lastTick >= 1000) {
			fpsCounter.setText(frameCount);
			frameCount = 0;
			lastTick = now;
			var gameElapsedTime = Math.floor((now - gameStartTime) / 1000);
			gameTimerCounter.setText(gameElapsedTime.toString());
		}
		hero.update();
		if (hero.x < leftWall.width + 0.025 * 2048) hero.x = leftWall.width + 0.025 * 2048;
		if (hero.x > 2048 - rightWall.width - 0.025 * 2048) hero.x = 2048 - rightWall.width - 0.025 * 2048;
		if (hero.y < topWall.height + 0.025 * 2732) hero.y = topWall.height + 0.025 * 2732;
		if (hero.y > 2732 - bottomWall.height - 0.025 * 2732) hero.y = 2732 - bottomWall.height - 0.025 * 2732;
		enemies.forEach(function (enemy, index) {
			enemy.followHero(hero);
			for (var i = 0; i < enemies.length; i++) {
				if (i !== index) {
					var other = enemies[i];
					var dx = enemy.x - other.x;
					var dy = enemy.y - other.y;
					var distance = Math.sqrt(dx * dx + dy * dy);
					if (distance < enemy.graphics.width) {
						var overlap = enemy.graphics.width - distance;
						var adjustX = overlap / 2 * (dx / distance);
						var adjustY = overlap / 2 * (dy / distance);
						enemy.x += adjustX;
						enemy.y += adjustY;
						other.x -= adjustX;
						other.y -= adjustY;
					}
				}
			}
		});
		for (var a = heroBullets.length - 1; a >= 0; a--) {
			heroBullets[a].move();
			if (heroBullets[a].y < 0 || heroBullets[a].y > 2732 || heroBullets[a].x < 0 || heroBullets[a].x > 2048) {
				heroBullets[a].destroy();
				heroBullets.splice(a, 1);
			}
			for (var b = enemyBullets.length - 1; b >= 0; b--) {
				if (heroBullets[a].intersects(enemyBullets[b])) {
					heroBullets[a].destroy();
					enemyBullets[b].destroy();
					heroBullets.splice(a, 1);
					enemyBullets.splice(b, 1);
					break;
				}
			}
			for (var e = enemies.length - 1; e >= 0; e--) {
				if (heroBullets[a] && enemies[e] && heroBullets[a].intersects(enemies[e])) {
					var explosion = self.createAsset('explosion', 'Explosion Animation', .5, .5);
					explosion.x = enemies[e].x;
					explosion.y = enemies[e].y;
					enemies[e].destroy();
					enemies.splice(e, 1);
					heroBullets[a].destroy();
					heroBullets.splice(a, 1);
					LK.setTimeout(function () {
						explosion.destroy();
					}, 1000);
					break;
				}
			}
		}
		for (var a = enemyBullets.length - 1; a >= 0; a--) {
			if (enemyBullets[a]) {
				enemyBullets[a].move();
				if (enemyBullets[a].y > 2732 + 50) {
					enemyBullets[a].destroy();
					enemyBullets.splice(a, 1);
				}
				if (hero.intersects(enemyBullets[a])) {
					isGameOver = true;
				}
			}
		}
		var lastBulletTime = 0;
		var bulletFireRate = 1000;
		var lastBulletTime = 0;
		var bulletFireRate = 500;
		var lastBulletTime = 0;
		var lastTouchTime = 0;
		var touchDelay = 10000;
		stage.on('down', function (obj) {
			if (self.startingScene) {
				self.startingScene = false;
				var spawnEnemy = function () {
					var newEnemy = self.addChild(new Enemy());
					newEnemy.x = Math.random() * 2048;
					newEnemy.y = Math.random() * 2732;
					newEnemy.scale.x = newEnemy.scale.y = Math.random() * 2 + 0.5;
					enemies.push(newEnemy);
					LK.setTimeout(spawnEnemy, 2000);
				};
				LK.setTimeout(spawnEnemy, 2000);
				return;
			}
			var now = Date.now();
			if (now - lastTouchTime < touchDelay) return;
			lastTouchTime = now;
			if (now - lastBulletTime < bulletFireRate) return;
			lastBulletTime = now;
			var event = obj.event;
			var pos = event.getLocalPosition(self);
			var newBullet = new HeroBullet();
			newBullet.x = hero.x;
			newBullet.y = hero.y;
			var dx = pos.x - hero.x;
			var dy = pos.y - hero.y;
			var mag = Math.sqrt(dx * dx + dy * dy);
			newBullet.speedX = 10 * dx / mag;
			newBullet.speedY = 10 * dy / mag;
			heroBullets.push(newBullet);
			self.addChild(newBullet);
			hero.knockback(-dx / (mag * 10), -dy / (mag * 10));
			if (dx < 0) {
				hero.scale.x = 1;
			} else {
				hero.scale.x = -1;
			}
		});
	});
});

===================================================================
--- original.js
+++ change.js
@@ -70,13 +70,17 @@
 	startButton.on('down', function () {
 		self.removeChild(startButton);
 		hero = self.addChild(new Hero());
 		var enemies = [];
-		var newEnemy = self.addChild(new Enemy());
-		enemies.push(newEnemy);
-		hero.x = 1024;
-		hero.y = 1366;
-		self.startingScene = false;
+		startButton.on('down', function () {
+			self.removeChild(startButton);
+			hero = self.addChild(new Hero());
+			var newEnemy = self.addChild(new Enemy());
+			enemies.push(newEnemy);
+			hero.x = 1024;
+			hero.y = 1366;
+			self.startingScene = false;
+		});
 	});
 	var leftWall = self.addChild(new Wall());
 	leftWall.width = 81.92;
 	leftWall.height = 2732;