/**** 
* Classes
****/ 
// City class: represents a city to defend
var City = Container.expand(function () {
	var self = Container.call(this);
	var cityAsset = self.attachAsset('city', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.width = cityAsset.width;
	self.height = cityAsset.height;
	self.destroyed = false;
	self.destroyCity = function () {
		self.destroyed = true;
		self.visible = false;
	};
	return self;
});
// --- Game Variables ---
// CounterMissile class: player's missile
var CounterMissile = Container.expand(function () {
	var self = Container.call(this);
	var missileAsset = self.attachAsset('counterMissile', {
		anchorX: 0.5,
		anchorY: 1.0
	});
	self.speed = 24;
	self.targetX = 0;
	self.targetY = 0;
	self.lastX = self.x;
	self.lastY = self.y;
	self.setTarget = function (x, y) {
		self.targetX = x;
		self.targetY = y;
		var dx = self.targetX - self.x;
		var dy = self.targetY - self.y;
		var dist = Math.sqrt(dx * dx + dy * dy);
		self.vx = dx / dist * self.speed;
		self.vy = dy / dist * self.speed;
		// Rotate missile to face direction of travel
		if (dist > 0) {
			// The missile asset points up (anchorY: 1.0), so angle is atan2(dx, -dy)
			// But for standard missile, use atan2(dx, -dy) or atan2(-dy, dx) depending on asset orientation
			// Here, asset points up, so rotation = Math.atan2(dx, -dy)
			// But in PIXI, rotation 0 is to the right, so to point up, use Math.atan2(dx, -dy)
			// Actually, to point the missile in the direction of travel, use Math.atan2(dx, -dy)
			// But in practice, for a missile pointing up, rotation = Math.atan2(dx, -dy)
			// Let's use Math.atan2(dx, -dy)
			self.rotation = Math.atan2(dx, -dy);
		}
	};
	self.update = function () {
		self.x += self.vx;
		self.y += self.vy;
		// Continuously update rotation to face direction of travel
		if (self.vx !== 0 || self.vy !== 0) {
			self.rotation = Math.atan2(self.vx, -self.vy);
		}
	};
	return self;
});
// EnemyMissile class: descending enemy missile
var EnemyMissile = Container.expand(function () {
	var self = Container.call(this);
	var missileAsset = self.attachAsset('enemyMissile', {
		anchorX: 0.5,
		anchorY: 0.0
	});
	self.speed = 6; // Default, will be overridden on spawn
	self.targetX = 200 + Math.random() * (2048 - 400);
	self.targetY = 2200 + Math.random() * 400;
	self.lastY = self.y;
	self.update = function () {
		// Move towards target
		var dx = self.targetX - self.x;
		var dy = self.targetY - self.y;
		var dist = Math.sqrt(dx * dx + dy * dy);
		if (dist > 0) {
			self.x += dx / dist * self.speed;
			self.y += dy / dist * self.speed;
		}
	};
	return self;
});
// Explosion class: visual effect for missile hit
var Explosion = Container.expand(function () {
	var self = Container.call(this);
	// Use a simple ellipse shape for explosion
	var explosionAsset = self.attachAsset('centerCircle', {
		anchorX: 0.5,
		anchorY: 0.5,
		scaleX: 1,
		scaleY: 1,
		alpha: 0.7
	});
	self.life = 18; // frames (0.3s at 60fps)
	self.age = 0;
	self.update = function () {
		self.age++;
		// Animate: grow and fade out
		explosionAsset.scaleX = explosionAsset.scaleY = 1 + self.age * 0.15;
		explosionAsset.alpha = Math.max(0, 0.7 * (1 - self.age / self.life));
		if (self.age >= self.life) {
			self.destroy();
		}
	};
	return self;
});
// Player class: controls the anti-missile battery
var Player = Container.expand(function () {
	var self = Container.call(this);
	var playerAsset = self.attachAsset('playerBattery', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = playerAsset.width;
	self.height = playerAsset.height;
	self.update = function () {};
	return self;
});

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

/**** 
* Game Code
****/ 
// --- Game Variables ---
var player;
var cities = [];
var enemyMissiles = [];
var counterMissiles = [];
var scoreText;
var spawnTimer;
var gameOver = false;
// Cooldown for counter missile firing
var canFire = true;
var fireCooldownTimer = null;
// --- Add background image ---
var background = LK.getAsset('background', {
	anchorX: 0,
	anchorY: 0,
	x: 0,
	y: 0,
	width: 2048,
	height: 2732
});
game.addChildAt(background, 0);
// --- Setup Game Elements ---
function setupGame() {
	// Add player battery at bottom center
	player = new Player();
	player.x = 2048 / 2;
	player.y = 2350;
	game.addChild(player);
	// Add cities to defend
	var cityCount = 5;
	var spacing = 2048 / (cityCount + 1);
	for (var i = 0; i < cityCount; i++) {
		var city = new City();
		city.x = spacing * (i + 1);
		city.y = 2650;
		game.addChild(city);
		cities.push(city);
	}
	;
	// --- Update explosions ---
	if (typeof explosions === "undefined") {
		explosions = [];
	}
	// Find all explosions in game.children and update them, remove if destroyed
	for (var i = game.children.length - 1; i >= 0; i--) {
		var obj = game.children[i];
		if (obj && obj.update && obj.constructor && obj.constructor.name === "Explosion") {
			obj.update();
			if (obj.destroyed) {
				game.removeChild(obj);
			}
		}
	}
	// Score text
	scoreText = new Text2('0', {
		size: 120,
		fill: "#fff"
	});
	scoreText.anchor.set(0.5, 0);
	LK.gui.top.addChild(scoreText);
	// Start enemy missile spawn timer
	spawnTimer = LK.setInterval(spawnEnemyMissile, 60 * 8);
}
// --- Calculate enemy missile speed based on score ---
function getEnemyMissileSpeed() {
	// Base speed is 6, increases up to +10 as score increases, capped at 16
	var base = 6;
	var max = 16;
	var score = LK.getScore();
	var speed = base + Math.min(10, Math.floor(score / 500));
	return Math.min(speed, max);
}
// --- Enemy Missile Spawner ---
function spawnEnemyMissile() {
	if (gameOver) return;
	var missile = new EnemyMissile();
	missile.x = 200 + Math.random() * (2048 - 400);
	missile.y = -80;
	missile.speed = getEnemyMissileSpeed();
	// Target a random city that is not destroyed
	var aliveCities = cities.filter(function (c) {
		return !c.destroyed;
	});
	if (aliveCities.length === 0) return;
	var targetCity = aliveCities[Math.floor(Math.random() * aliveCities.length)];
	missile.targetX = targetCity.x;
	missile.targetY = targetCity.y - 40;
	enemyMissiles.push(missile);
	game.addChild(missile);
}
// --- Game Touch: Launch CounterMissile ---
game.down = function (x, y, obj) {
	if (gameOver) return;
	if (!canFire) return;
	// Only allow firing from above the player
	if (y < player.y - 100) {
		var missile = new CounterMissile();
		missile.x = player.x;
		missile.y = player.y - 60;
		missile.setTarget(x, y);
		counterMissiles.push(missile);
		game.addChild(missile);
		// Start cooldown
		canFire = false;
		if (fireCooldownTimer !== null) {
			LK.clearTimeout(fireCooldownTimer);
		}
		fireCooldownTimer = LK.setTimeout(function () {
			canFire = true;
			fireCooldownTimer = null;
		}, 300);
	}
};
// --- Game Update Loop ---
game.update = function () {
	if (gameOver) return;
	// Update enemy missiles
	for (var i = enemyMissiles.length - 1; i >= 0; i--) {
		var em = enemyMissiles[i];
		em.update();
		// Check if hit a city
		for (var j = 0; j < cities.length; j++) {
			var city = cities[j];
			if (!city.destroyed && em.intersects(city)) {
				// Spawn explosion at city location
				var explosion = new Explosion();
				explosion.x = city.x;
				explosion.y = city.y - city.height / 2;
				game.addChild(explosion);
				city.destroyCity();
				em.destroy();
				enemyMissiles.splice(i, 1);
				// Check for game over
				if (cities.filter(function (c) {
					return !c.destroyed;
				}).length === 0) {
					gameOver = true;
					LK.showGameOver();
				}
				break;
			}
		}
		// Remove if off screen
		if (em.y > 2732) {
			em.destroy();
			enemyMissiles.splice(i, 1);
		}
	}
	// Update counter missiles
	for (var i = counterMissiles.length - 1; i >= 0; i--) {
		var cm = counterMissiles[i];
		cm.update();
		// Remove if off screen
		if (cm.x < 0 || cm.x > 2048 || cm.y < 0 || cm.y > 2732) {
			cm.destroy();
			counterMissiles.splice(i, 1);
			continue;
		}
		// Check for collision with enemy missiles
		for (var j = enemyMissiles.length - 1; j >= 0; j--) {
			var em = enemyMissiles[j];
			if (cm.intersects(em)) {
				// Spawn explosion at collision point
				var explosion = new Explosion();
				explosion.x = em.x;
				explosion.y = em.y;
				game.addChild(explosion);
				// Destroy both
				cm.destroy();
				em.destroy();
				counterMissiles.splice(i, 1);
				enemyMissiles.splice(j, 1);
				// Score
				LK.setScore(LK.getScore() + 100);
				scoreText.setText(LK.getScore());
				break;
			}
		}
	}
};
// --- Start Game ---
setupGame();

===================================================================
--- original.js
+++ change.js
@@ -140,8 +140,18 @@
 var gameOver = false;
 // Cooldown for counter missile firing
 var canFire = true;
 var fireCooldownTimer = null;
+// --- Add background image ---
+var background = LK.getAsset('background', {
+	anchorX: 0,
+	anchorY: 0,
+	x: 0,
+	y: 0,
+	width: 2048,
+	height: 2732
+});
+game.addChildAt(background, 0);
 // --- Setup Game Elements ---
 function setupGame() {
 	// Add player battery at bottom center
 	player = new Player();