/**** 
* Classes
****/
// Define the Hero class
var Hero = Container.expand(function () {
	var self = Container.call(this);
	var heroGraphics = self.createAsset('hero', 'Hero character', 0.5, 0.5);
	self.torchGraphics = self.createAsset('torch', 'Hero torch', 0.5, 0);
	self.torchGraphics.visible = false;
	self.orientTorch = function (mousePos) {
		var angle = Math.atan2(mousePos.y - self.y, mousePos.x - self.x);
		torchGraphics.rotation = angle;
		torchGraphics.visible = true;
	};
	self.speed = 5;
	self.shoot = function () {
		var bullet = new HeroBullet();
		bullet.x = self.x;
		bullet.y = self.y;
		game.addChild(bullet);
		bullets.push(bullet);
	};
	self.move = function (direction) {
		self.x += direction.x * self.speed;
		self.y += direction.y * self.speed;
	};
});
// Define the HeroBullet class
var HeroBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.createAsset('heroBullet', 'Hero bullet', 0.5, 1);
	self.speed = -10;
	self.move = function () {
		self.y += self.speed;
	};
});
// Define the Zombie class
var Zombie = Container.expand(function () {
	var self = Container.call(this);
	var zombieGraphics = self.createAsset('zombie', 'Zombie enemy', 0.5, 0.5);
	self.speed = 1;
	self.move = function (torchPos, torchAngle) {
		self.y += self.speed;
		if (torchPos) {
			var angleToZombie = Math.atan2(self.y - torchPos.y, self.x - torchPos.x);
			var angleDifference = Math.abs(torchAngle - angleToZombie);
			if (angleDifference < 0.5) {
				// Assuming torch has a cone of visibility of 0.5 radians
				self.visible = true;
			} else {
				self.visible = false;
			}
		}
	};
});

/**** 
* Initialize Game
****/
var game = new LK.Game({
	backgroundColor: 0x000000 // Init game with black background
});

/**** 
* Game Code
****/
// Initialize important asset arrays
var bullets = [];
var zombies = [];
var hero;
var isGameOver = false;
// Create the hero
hero = game.addChild(new Hero());
hero.x = 2048 / 2;
hero.y = 2732 - 100; // Position hero near the bottom of the screen
// Game logic and event handlers
LK.on('keydown', function (obj) {
	var direction = {
		x: 0,
		y: 0
	};
	var e = obj.event;
	switch (e.keyCode) {
		case 37:
			// left arrow
			direction.x = -1;
			break;
		case 39:
			// right arrow
			direction.x = 1;
			break;
		case 38:
			// up arrow
			direction.y = -1;
			break;
		case 40:
			// down arrow
			direction.y = 1;
			break;
	}
	hero.move(direction);
});
LK.on('tick', function () {
	if (isGameOver) {
		LK.showGameOver();
		return;
	}
	// Move bullets and check for off-screen
	for (var i = bullets.length - 1; i >= 0; i--) {
		bullets[i].move();
		if (bullets[i].y < 0) {
			bullets[i].destroy();
			bullets.splice(i, 1);
		}
	}
	// Handle torch orientation and make zombies visible if illuminated
	var torchPos = {
		x: hero.x,
		y: hero.y
	};
	var torchAngle = hero.torchGraphics.rotation;
	// Move zombies and check for collision with hero
	for (var j = zombies.length - 1; j >= 0; j--) {
		zombies[j].move(torchPos, torchAngle);
		if (zombies[j].y > 2732) {
			zombies[j].destroy();
			zombies.splice(j, 1);
		} else if (zombies[j].intersects(hero) && zombies[j].visible) {
			isGameOver = true;
		}
	}
	for (var j = zombies.length - 1; j >= 0; j--) {
		zombies[j].move();
		if (zombies[j].y > 2732) {
			zombies[j].destroy();
			zombies.splice(j, 1);
		} else if (zombies[j].intersects(hero)) {
			isGameOver = true;
		}
	}
	game.on('move', function (obj) {
		var mousePos = obj.event.getLocalPosition(game);
		hero.orientTorch(mousePos);
	});
	// Spawn zombies
	if (LK.ticks % 120 == 0) {
		// Spawn a zombie every 2 seconds
		var zombie = new Zombie();
		zombie.x = Math.random() * 2048;
		zombie.y = -50; // Start off-screen
		zombies.push(zombie);
		game.addChild(zombie);
	}
});

===================================================================
--- original.js
+++ change.js
@@ -40,15 +40,17 @@
 	var zombieGraphics = self.createAsset('zombie', 'Zombie enemy', 0.5, 0.5);
 	self.speed = 1;
 	self.move = function (torchPos, torchAngle) {
 		self.y += self.speed;
-		var angleToZombie = Math.atan2(self.y - torchPos.y, self.x - torchPos.x);
-		var angleDifference = Math.abs(torchAngle - angleToZombie);
-		if (angleDifference < 0.5) {
-			// Assuming torch has a cone of visibility of 0.5 radians
-			self.visible = true;
-		} else {
-			self.visible = false;
+		if (torchPos) {
+			var angleToZombie = Math.atan2(self.y - torchPos.y, self.x - torchPos.x);
+			var angleDifference = Math.abs(torchAngle - angleToZombie);
+			if (angleDifference < 0.5) {
+				// Assuming torch has a cone of visibility of 0.5 radians
+				self.visible = true;
+			} else {
+				self.visible = false;
+			}
 		}
 	};
 });