/**** 
* Classes
****/ 
// Define a class for bullets
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 10;
	self.update = function () {
		self.x += self.speedX;
		self.y += self.speedY;
		if (self.x > 2048 + 50 || self.y < -50) {
			self.destroy();
		}
	};
});
// Define a class for enemies
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	var enemyAssetId = LK.getScore() >= 90 ? 'Enemy10' : LK.getScore() >= 80 ? 'Enemy9' : LK.getScore() >= 70 ? 'Enemy8' : LK.getScore() >= 60 ? 'Enemy7' : LK.getScore() >= 50 ? 'Enemy6' : LK.getScore() >= 40 ? 'Enemy5' : LK.getScore() >= 30 ? 'enemy4' : LK.getScore() >= 20 ? 'enemy3' : LK.getScore() >= 10 ? 'enemy2' : 'enemy';
	var enemyGraphics = self.attachAsset(enemyAssetId, {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 5 + Math.floor(LK.getScore() / 20);
	self.update = function () {
		self.x -= self.speed;
		self.y += Math.sin(LK.ticks / 20) * 5; // Make enemy fly up and down
		if (enemyAssetId === 'enemy2' || enemyAssetId === 'enemy3') {
			self.y += Math.sin(LK.ticks / 10) * 10; // Make enemy2 and enemy3 fly in small circles
			self.x += Math.cos(LK.ticks / 10) * 10; // Add horizontal movement for circular path
		}
		if (self.y > 1366) {
			// Ensure enemies stay in the top half of the screen
			self.y = 1366;
		}
		if (self.x < -50) {
			self.destroy();
		}
	};
});
// Define a class for a steady moving background
var MovingBackground = Container.expand(function () {
	var self = Container.call(this);
	var bg1 = self.attachAsset('background', {
		anchorX: 0,
		anchorY: 0
	});
	var bg2 = self.attachAsset('background2', {
		anchorX: 0,
		anchorY: 0
	});
	bg1.x = 0;
	bg2.x = 2048; // Position the second background right after the first one
	self.speed = 4 + Math.floor(LK.getScore() / 50);
	self.update = function () {
		bg1.x -= self.speed;
		bg2.x -= self.speed;
		// Reset positions to create a continuous loop
		if (bg1.x <= -2048) {
			bg1.x = bg2.x + 2048;
		}
		if (bg2.x <= -2048) {
			bg2.x = bg1.x + 2048;
		}
	};
});
//<Assets used in the game will automatically appear here>
// Define a class for the player character
var Player = Container.expand(function () {
	var self = Container.call(this);
	var playerGraphics = self.attachAsset('player', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.lives = 3;
	self.speed = 5;
	self.jumpHeight = 40;
	self.update = function () {};
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x87CEEB // Sky blue background
});

/**** 
* Game Code
****/ 
var movingBackground = game.addChild(new MovingBackground());
LK.getSound('Startmusic').play();
// Initialize player
var player = game.addChild(new Player());
player.x = 2048 / 2 - 600; // Move player further back
player.y = 2732 / 2 - 100; // Move player up a bit
// Initialize enemies
var enemies = [];
var enemySpawnInterval = 100;
var enemySpawnCounter = 0;
// Create a new Text2 object to display the score
var scoreText = new Text2('0', {
	size: 100,
	fill: 0xFFFFFF
});
// Add the score text to the game GUI at the top center of the screen
LK.gui.top.addChild(scoreText);
scoreText.anchor.set(0.5, 0); // Center the score text horizontally
scoreText.x = 2048 / 2;
scoreText.y = 0;
// Create a new Text2 object to display the level
var levelText = new Text2('Level 1', {
	size: 100,
	fill: 0xFFFFFF
});
// Add the level text to the game GUI at the top left of the screen
LK.gui.topLeft.addChild(levelText);
levelText.x = 20;
levelText.y = 0;
// Create a new Text2 object to display the lives
var livesText = new Text2('Lives: 3', {
	size: 100,
	fill: 0xFFFFFF
});
// Add the lives text to the game GUI at the top right of the screen
LK.gui.topRight.addChild(livesText);
livesText.x = -20 - livesText.width;
livesText.y = 0;
// Add the score text next to the level text
scoreText.x = levelText.x + levelText.width + 20 - 300;
scoreText.y = levelText.y;
// Handle game updates
game.update = function () {
	player.update();
	movingBackground.update();
	// Spawn enemies
	enemySpawnCounter++;
	if (enemySpawnCounter >= enemySpawnInterval) {
		// Add more enemies every 10 points
		if (LK.getScore() % 10 === 0 && LK.getScore() !== 0) {
			// Check if the player has reached level 11
			if (Math.floor(LK.getScore() / 10) + 1 >= 11) {
				LK.showYouWin(); // Show "you win" screen
				return; // Exit the update function to prevent further updates
			}
			// Update level text
			var currentLevel = Math.floor(LK.getScore() / 10) + 1;
			levelText.setText('Level ' + currentLevel);
			for (var i = 0; i < 2; i++) {
				// Add two enemies
				var extraEnemy = new Enemy();
				extraEnemy.x = 2048;
				extraEnemy.y = Math.random() * (2732 / 2); // Randomize Y position in the top half
				enemies.push(extraEnemy);
				game.addChild(extraEnemy);
			}
		}
		var enemy = new Enemy();
		enemy.x = 2048;
		enemy.y = Math.random() * (2732 / 2); // Randomize Y position in the top half to allow flying
		enemies.push(enemy);
		game.addChild(enemy);
		// Randomize the spawn interval for the next enemy
		enemySpawnInterval = Math.floor(Math.random() * 150) + 50;
		enemySpawnCounter = 0;
	}
	// Update enemies
	for (var j = enemies.length - 1; j >= 0; j--) {
		enemies[j].update();
		if (player.intersects(enemies[j])) {
			LK.effects.flashScreen(0xff0000, 1000);
			player.lives -= 1;
			livesText.setText('Lives: ' + player.lives);
			if (player.lives <= 0) {
				LK.showGameOver();
			}
			enemies[j].destroy();
			enemies.splice(j, 1);
			continue;
		}
		// Check for bullet collision with enemies
		for (var i = game.children.length - 1; i >= 0; i--) {
			if (game.children[i] instanceof Bullet && game.children[i].intersects(enemies[j])) {
				// Create explosion effect
				var explosion = LK.getAsset('fire', {
					anchorX: 0.5,
					anchorY: 0.5,
					x: enemies[j].x,
					y: enemies[j].y
				});
				game.addChild(explosion);
				// Remove explosion after a short delay
				LK.setTimeout(function () {
					explosion.destroy();
				}, 500);
				if (game.children[i]) {
					game.children[i].destroy();
				}
				enemies[j].destroy();
				if (enemies[j].attachAsset('enemy2')) {
					// Check if the player has reached 50 kills
					if (LK.getScore() % 50 === 0 && LK.getScore() !== 0) {
						// Add 1up asset in front of the player
						var oneUp = LK.getAsset('1up', {
							anchorX: 0.5,
							anchorY: 0.5,
							x: player.x + player.width + 50,
							// Position it in front of the player
							y: player.y
						});
						game.addChild(oneUp);
						// Allow player to collect 1up for extra life
						oneUp.update = function () {
							for (var i = game.children.length - 1; i >= 0; i--) {
								if (game.children[i] instanceof Bullet && game.children[i].intersects(oneUp)) {
									player.lives += 1;
									livesText.setText('Lives: ' + player.lives);
									LK.getSound('1up').play();
									oneUp.destroy();
									if (game.children[i]) {
										game.children[i].destroy();
									}
									break;
								}
							}
						};
					}
					LK.getSound('enemy2_destroyed').play();
				} else {
					LK.getSound('enemy_destroyed').play();
				}
				LK.setScore(LK.getScore() + 1); // Add 1 point to score
				scoreText.setText(LK.getScore());
				enemies.splice(j, 1);
				break;
				enemies.splice(j, 1);
				break;
			}
		}
	}
};
// Handle player jump
game.down = function (x, y, obj) {
	// Check if the number of bullets on screen is less than 3
	var bulletCount = 0;
	for (var i = 0; i < game.children.length; i++) {
		if (game.children[i] instanceof Bullet) {
			bulletCount++;
		}
	}
	if (bulletCount < 3) {
		var newBullet = new Bullet();
		var angle = Math.atan2(y - player.y, x - player.x);
		newBullet.x = player.x + player.width / 2; // Adjust the bullet's initial x position to the cannon's position
		newBullet.y = player.y; // Adjust the bullet's initial y position to the cannon's position
		newBullet.speedX = Math.cos(angle) * newBullet.speed;
		newBullet.speedY = Math.sin(angle) * newBullet.speed;
		game.addChild(newBullet);
		LK.getSound('shoot').play();
	}
};

===================================================================
--- original.js
+++ change.js
@@ -220,9 +220,11 @@
 									player.lives += 1;
 									livesText.setText('Lives: ' + player.lives);
 									LK.getSound('1up').play();
 									oneUp.destroy();
-									game.children[i].destroy();
+									if (game.children[i]) {
+										game.children[i].destroy();
+									}
 									break;
 								}
 							}
 						};