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);
	LK.stageContainer.setBackgroundColor(0x000000);
	var hero = self.addChild(new Hero());
	var enemies = [];
	hero.x = 1024;
	hero.y = 1366;
	var leftWallTop = self.addChild(new Wall());
	leftWallTop.width = 40.96;
	leftWallTop.height = 1366;
	leftWallTop.x = 0;
	leftWallTop.y = 0;
	var leftWallBottom = self.addChild(new Wall());
	leftWallBottom.width = 81.92;
	leftWallBottom.height = 1366;
	leftWallBottom.x = 0;
	leftWallBottom.y = 1366;
	var rightWallTop = self.addChild(new Wall());
	rightWallTop.width = 40.96;
	rightWallTop.height = 1366;
	rightWallTop.x = 2048 - 40.96;
	rightWallTop.y = 0;
	var rightWallBottom = self.addChild(new Wall());
	rightWallBottom.width = 81.92;
	rightWallBottom.height = 1366;
	rightWallBottom.x = 2048 - 81.92;
	rightWallBottom.y = 1366;
	var topWallLeft = self.addChild(new Wall());
	topWallLeft.width = 1024;
	topWallLeft.height = 54.64;
	topWallLeft.x = 0;
	topWallLeft.y = 0;
	var topWallRight = self.addChild(new Wall());
	topWallRight.width = 1024;
	topWallRight.height = 109.28;
	topWallRight.x = 1024;
	topWallRight.y = 0;
	var bottomWallLeft = self.addChild(new Wall());
	bottomWallLeft.width = 1024;
	bottomWallLeft.height = 54.64;
	bottomWallLeft.x = 0;
	bottomWallLeft.y = 2732 - 54.64;
	var bottomWallRight = self.addChild(new Wall());
	bottomWallRight.width = 1024;
	bottomWallRight.height = 109.28;
	bottomWallRight.x = 1024;
	bottomWallRight.y = 2732 - 109.28;
	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);
	};
	spawnEnemy();
	var enemySpawnInterval = LK.setInterval(spawnEnemy, 7000);
	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 (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((Date.now() - gameStartTime) / 1000);
			gameTimerCounter.setText(gameElapsedTime.toString());
		}
		hero.update();
		if (hero.x < leftWallTop.width + 0.025 * 2048) hero.x = leftWallTop.width + 0.025 * 2048;
		if (hero.x > 2048 - rightWallTop.width - 0.025 * 2048) hero.x = 2048 - rightWallTop.width - 0.025 * 2048;
		if (hero.y < topWallLeft.height + 0.025 * 2732) hero.y = topWallLeft.height + 0.025 * 2732;
		if (hero.y < topWallRight.height + 0.025 * 2732) hero.y = topWallRight.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])) {
					heroBullets[a].destroy();
					enemies[e].destroy();
					heroBullets.splice(a, 1);
					enemies.splice(e, 1);
					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);
				}
			}
		}
		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) {
			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
@@ -148,9 +148,10 @@
 		}
 		hero.update();
 		if (hero.x < leftWallTop.width + 0.025 * 2048) hero.x = leftWallTop.width + 0.025 * 2048;
 		if (hero.x > 2048 - rightWallTop.width - 0.025 * 2048) hero.x = 2048 - rightWallTop.width - 0.025 * 2048;
-		if (hero.y < topWall.height + 0.025 * 2732) hero.y = topWall.height + 0.025 * 2732;
+		if (hero.y < topWallLeft.height + 0.025 * 2732) hero.y = topWallLeft.height + 0.025 * 2732;
+		if (hero.y < topWallRight.height + 0.025 * 2732) hero.y = topWallRight.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++) {