/**** 
* Classes
****/
// Hero class
var Hero = Container.expand(function () {
	var self = Container.call(this);
	var heroGraphics = self.attachAsset('hero', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.update = function () {
		// Hero update logic
	};
	self.powerUpActive = false;
	self.powerUpEndTime = 0;
	self.shoot = function () {
		if (self.powerUpActive) {
			var bullet1 = new HeroBullet();
			bullet1.x = self.x - 20;
			bullet1.y = self.y - self.height / 2;
			game.addChild(bullet1);
			var bullet2 = new HeroBullet();
			bullet2.x = self.x + 20;
			bullet2.y = self.y - self.height / 2;
			game.addChild(bullet2);
			heroBullets.push(bullet1, bullet2);
		} else {
			var bullet = new HeroBullet();
			bullet.x = self.x;
			bullet.y = self.y - self.height / 2;
			heroBullets.push(bullet);
			game.addChild(bullet);
		}
	};
});
// Enemy class
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	var enemyGraphics = self.attachAsset('enemy', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 2;
	self.move = function () {
		self.y += self.speed;
	};
	self.shoot = function () {
		// Enemy shooting logic
	};
});
// HeroBullet class
var HeroBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('heroBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -10;
	self.move = function () {
		self.y += self.speed;
	};
});
// EnemyBullet class
var EnemyBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('enemyBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 5;
	self.move = function () {
		self.y += self.speed;
	};
});
// SupplyBox class
var SupplyBox = Container.expand(function () {
	var self = Container.call(this);
	var supplyBoxGraphics = self.attachAsset('supplyBox', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.active = false;
	self.activatePowerUp = function (hero) {
		hero.powerUpActive = true;
		hero.powerUpEndTime = LK.ticks + 20 * 60; // 20 seconds at 60FPS
	};
});

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

/**** 
* Game Code
****/
// Define assets for the hero, enemies, and bullets
// Initialize hero
var hero = game.addChild(new Hero());
hero.x = 2048 / 2;
hero.y = 2732 - 150;
// Initialize arrays for bullets and enemies, and declare supplyBox
var heroBullets = [];
var enemyBullets = [];
var enemies = [];
var supplyBox;
// Game tick event
LK.on('tick', function () {
	// Update hero
	hero.update();
	// Move and check hero bullets
	for (var i = heroBullets.length - 1; i >= 0; i--) {
		heroBullets[i].move();
		for (var k = enemies.length - 1; k >= 0; k--) {
			if (heroBullets[i] && heroBullets[i].intersects(enemies[k])) {
				enemies[k].destroy();
				enemies.splice(k, 1);
				heroBullets[i].destroy();
				heroBullets.splice(i, 1);
				break;
			}
		}
		if (heroBullets[i] && heroBullets[i].y < 0) {
			heroBullets[i].destroy();
			heroBullets.splice(i, 1);
		}
	}
	// Move and check enemy bullets
	for (var j = enemyBullets.length - 1; j >= 0; j--) {
		enemyBullets[j].move();
		if (enemyBullets[j].intersects(hero)) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
		}
		if (enemyBullets[j] && enemyBullets[j].y > 2732) {
			enemyBullets[j].destroy();
			enemyBullets.splice(j, 1);
		}
	}
	// Move enemies, check for game over, and handle supply box collision
	for (var k = enemies.length - 1; k >= 0; k--) {
		enemies[k].move();
		if (enemies[k].y > 2732) {
			LK.showGameOver();
		}
	}
	// Handle hero power-up duration
	if (hero.powerUpActive && LK.ticks > hero.powerUpEndTime) {
		hero.powerUpActive = false;
	}
	// Check for hero collision with supply box
	if (supplyBox && !supplyBox.active && hero.intersects(supplyBox)) {
		supplyBox.activatePowerUp(hero);
		supplyBox.active = true;
		supplyBox.destroy();
		supplyBox = null;
	}
	// Spawn supply box at a random interval
	if (!supplyBox && LK.ticks % 600 == 0) {
		// Every 10 seconds
		supplyBox = new SupplyBox();
		supplyBox.x = Math.random() * (2048 - supplyBox.width) + supplyBox.width / 2;
		supplyBox.y = -supplyBox.height / 2;
		game.addChild(supplyBox);
	}
	// Spawn enemies
	if (LK.ticks % 120 == 0) {
		var newEnemy = new Enemy();
		newEnemy.x = Math.random() * (2048 - newEnemy.width) + newEnemy.width / 2;
		newEnemy.y = -newEnemy.height / 2;
		enemies.push(newEnemy);
		game.addChild(newEnemy);
	}
});
// Touch event to move hero
game.on('down', function (obj) {
	var pos = obj.event.getLocalPosition(game);
	hero.x = pos.x;
});
// Touch event to shoot
game.on('up', function (obj) {
	var bullet = new HeroBullet();
	bullet.x = hero.x;
	bullet.y = hero.y - hero.height / 2;
	heroBullets.push(bullet);
	game.addChild(bullet);
});

===================================================================
--- original.js
+++ change.js
@@ -104,9 +104,9 @@
 // Initialize arrays for bullets and enemies, and declare supplyBox
 var heroBullets = [];
 var enemyBullets = [];
 var enemies = [];
-var supplyBox = null;
+var supplyBox;
 // Game tick event
 LK.on('tick', function () {
 	// Update hero
 	hero.update();
@@ -157,9 +157,9 @@
 		supplyBox.destroy();
 		supplyBox = null;
 	}
 	// Spawn supply box at a random interval
-	if (LK.ticks % 600 == 0) {
+	if (!supplyBox && LK.ticks % 600 == 0) {
 		// Every 10 seconds
 		supplyBox = new SupplyBox();
 		supplyBox.x = Math.random() * (2048 - supplyBox.width) + supplyBox.width / 2;
 		supplyBox.y = -supplyBox.height / 2;