/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");

/**** 
* Classes
****/ 
// Asteroid
var Asteroid = Container.expand(function () {
	var self = Container.call(this);
	var rock = self.attachAsset('asteroid', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 10 + Math.random() * 6;
	self.rotationSpeed = (Math.random() - 0.5) * 0.1;
	self.update = function () {
		self.y += self.speed;
		rock.rotation += self.rotationSpeed;
	};
	return self;
});
// Enemy bullet
var EnemyBullet = Container.expand(function () {
	var self = Container.call(this);
	var bullet = self.attachAsset('enemyBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 18;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
// Enemy ship
var EnemyShip = Container.expand(function () {
	var self = Container.call(this);
	var enemy = self.attachAsset('enemyShip', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 3 + Math.random() * 2;
	self.shootCooldown = 60 + Math.floor(Math.random() * 60);
	self.radius = enemy.width * 0.5;
	self.update = function () {
		self.y += self.speed;
		self.shootCooldown--;
	};
	return self;
});
// Player bullet
var PlayerBullet = Container.expand(function () {
	var self = Container.call(this);
	var bullet = self.attachAsset('playerBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -32;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
// Powerup
var Powerup = Container.expand(function () {
	var self = Container.call(this);
	var p = self.attachAsset('powerup', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 8;
	self.type = 'invincible';
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
// Player spaceship
var Spaceship = Container.expand(function () {
	var self = Container.call(this);
	var ship = self.attachAsset('spaceship', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.radius = ship.width * 0.5;
	self.invincible = false;
	self.invincibleTimer = 0;
	self.update = function () {
		if (self.invincible) {
			self.invincibleTimer--;
			if (self.invincibleTimer <= 0) {
				self.invincible = false;
				ship.alpha = 1;
			} else {
				ship.alpha = LK.ticks % 10 < 5 ? 0.5 : 1;
			}
		}
	};
	self.makeInvincible = function (duration) {
		self.invincible = true;
		self.invincibleTimer = duration;
		ship.alpha = 0.5;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x000010
});

/**** 
* Game Code
****/ 
// Powerup
// Asteroid
// Enemy bullet
// Enemy ship
// Player bullet
// Spaceship (player)
// Game variables
var player;
var playerBullets = [];
var enemies = [];
var enemyBullets = [];
var asteroids = [];
var powerups = [];
var dragNode = null;
var lastPlayerX = 0,
	lastPlayerY = 0;
var canShoot = true;
var shootCooldown = 0;
var score = 0;
var scoreTxt = new Text2('0', {
	size: 120,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
function spawnPlayer() {
	player = new Spaceship();
	player.x = 2048 / 2;
	player.y = 2732 - 350;
	game.addChild(player);
}
function spawnEnemy() {
	var enemy = new EnemyShip();
	enemy.x = 200 + Math.random() * (2048 - 400);
	enemy.y = -100;
	enemies.push(enemy);
	game.addChild(enemy);
}
function spawnAsteroid() {
	var asteroid = new Asteroid();
	asteroid.x = 150 + Math.random() * (2048 - 300);
	asteroid.y = -100;
	asteroids.push(asteroid);
	game.addChild(asteroid);
}
function spawnPowerup() {
	var powerup = new Powerup();
	powerup.x = 200 + Math.random() * (2048 - 400);
	powerup.y = -80;
	powerups.push(powerup);
	game.addChild(powerup);
}
function firePlayerBullet() {
	if (!player || player.invincible) return;
	var bullet = new PlayerBullet();
	bullet.x = player.x;
	bullet.y = player.y - player.radius;
	playerBullets.push(bullet);
	game.addChild(bullet);
}
function fireEnemyBullet(enemy) {
	var bullet = new EnemyBullet();
	bullet.x = enemy.x;
	bullet.y = enemy.y + enemy.radius;
	enemyBullets.push(bullet);
	game.addChild(bullet);
}
function resetGame() {
	// Not needed, handled by LK.showGameOver
}
// Dragging and shooting
game.down = function (x, y, obj) {
	if (!player) return;
	dragNode = player;
	lastPlayerX = x;
	lastPlayerY = y;
};
game.up = function (x, y, obj) {
	dragNode = null;
};
function handleMove(x, y, obj) {
	if (dragNode === player) {
		// Clamp to game area, avoid top 100px (menu)
		var minX = player.radius + 20;
		var maxX = 2048 - player.radius - 20;
		var minY = 120 + player.radius;
		var maxY = 2732 - player.radius - 20;
		player.x = Math.max(minX, Math.min(maxX, x));
		player.y = Math.max(minY, Math.min(maxY, y));
	}
}
game.move = handleMove;
// Tap to shoot (on any area)
game.tap = function (x, y, obj) {
	if (canShoot && !player.invincible) {
		firePlayerBullet();
		canShoot = false;
		shootCooldown = 10;
	}
};
// Main update loop
game.update = function () {
	// Player shooting cooldown
	if (!canShoot) {
		shootCooldown--;
		if (shootCooldown <= 0) {
			canShoot = true;
		}
	}
	// Update player
	if (player) player.update();
	// Update and remove player bullets
	for (var i = playerBullets.length - 1; i >= 0; i--) {
		var b = playerBullets[i];
		b.update();
		if (b.y < -80) {
			b.destroy();
			playerBullets.splice(i, 1);
			continue;
		}
		// Check collision with enemies
		for (var j = enemies.length - 1; j >= 0; j--) {
			var e = enemies[j];
			if (b.intersects(e)) {
				// Destroy both
				b.destroy();
				playerBullets.splice(i, 1);
				e.destroy();
				enemies.splice(j, 1);
				score += 100;
				scoreTxt.setText(score);
				break;
			}
		}
	}
	// Update and remove enemies
	for (var i = enemies.length - 1; i >= 0; i--) {
		var e = enemies[i];
		e.update();
		if (e.y > 2732 + 100) {
			e.destroy();
			enemies.splice(i, 1);
			continue;
		}
		// Enemy shooting
		if (e.shootCooldown <= 0) {
			fireEnemyBullet(e);
			e.shootCooldown = 90 + Math.floor(Math.random() * 60);
		}
		// Collision with player
		if (player && !player.invincible && e.intersects(player)) {
			LK.effects.flashScreen(0xff0000, 800);
			LK.showGameOver();
			return;
		}
	}
	// Update and remove enemy bullets
	for (var i = enemyBullets.length - 1; i >= 0; i--) {
		var b = enemyBullets[i];
		b.update();
		if (b.y > 2732 + 80) {
			b.destroy();
			enemyBullets.splice(i, 1);
			continue;
		}
		// Collision with player
		if (player && !player.invincible && b.intersects(player)) {
			LK.effects.flashScreen(0xff0000, 800);
			LK.showGameOver();
			return;
		}
	}
	// Update and remove asteroids
	for (var i = asteroids.length - 1; i >= 0; i--) {
		var a = asteroids[i];
		a.update();
		if (a.y > 2732 + 100) {
			a.destroy();
			asteroids.splice(i, 1);
			continue;
		}
		// Collision with player
		if (player && !player.invincible && a.intersects(player)) {
			LK.effects.flashScreen(0xff0000, 800);
			LK.showGameOver();
			return;
		}
	}
	// Update and remove powerups
	for (var i = powerups.length - 1; i >= 0; i--) {
		var p = powerups[i];
		p.update();
		if (p.y > 2732 + 80) {
			p.destroy();
			powerups.splice(i, 1);
			continue;
		}
		// Collision with player
		if (player && p.intersects(player)) {
			player.makeInvincible(120);
			p.destroy();
			powerups.splice(i, 1);
			score += 250;
			scoreTxt.setText(score);
			continue;
		}
	}
	// Spawning logic
	if (LK.ticks % 60 === 0) {
		spawnEnemy();
	}
	if (LK.ticks % 120 === 0) {
		spawnAsteroid();
	}
	if (LK.ticks % 600 === 0) {
		spawnPowerup();
	}
};
// Start game
spawnPlayer();

===================================================================
--- original.js
+++ change.js
@@ -40,9 +40,9 @@
 	var enemy = self.attachAsset('enemyShip', {
 		anchorX: 0.5,
 		anchorY: 0.5
 	});
-	self.speed = 6 + Math.random() * 4;
+	self.speed = 3 + Math.random() * 2;
 	self.shootCooldown = 60 + Math.floor(Math.random() * 60);
 	self.radius = enemy.width * 0.5;
 	self.update = function () {
 		self.y += self.speed;