===================================================================
--- original.js
+++ change.js
@@ -1,6 +1,448 @@
-/****
+/**** 
+* Plugins
+****/ 
+var tween = LK.import("@upit/tween.v1");
+
+/**** 
+* Classes
+****/ 
+// Enemy
+var Enemy = Container.expand(function () {
+	var self = Container.call(this);
+	self.type = 1; // 1,2,3
+	self.hp = 1;
+	self.shootTimer = 0;
+	self.pattern = 0; // 0: straight, 1: sine, 2: zigzag
+	self.baseX = 0;
+	self.baseY = 0;
+	self.t = 0;
+	self.speed = 4;
+	self.scoreValue = 10;
+	self.asset = null;
+	self.init = function (type, pattern) {
+		self.type = type;
+		self.pattern = pattern;
+		if (type === 1) {
+			self.asset = self.attachAsset('enemy1', {
+				anchorX: 0.5,
+				anchorY: 0.5
+			});
+			self.hp = 1;
+			self.scoreValue = 10;
+		} else if (type === 2) {
+			self.asset = self.attachAsset('enemy2', {
+				anchorX: 0.5,
+				anchorY: 0.5
+			});
+			self.hp = 2;
+			self.scoreValue = 20;
+		} else if (type === 3) {
+			self.asset = self.attachAsset('enemy3', {
+				anchorX: 0.5,
+				anchorY: 0.5
+			});
+			self.hp = 3;
+			self.scoreValue = 40;
+		}
+		self.width = self.asset.width;
+		self.height = self.asset.height;
+		self.baseX = self.x;
+		self.baseY = self.y;
+		self.t = 0;
+		self.shootTimer = 0;
+		self.speed = 4 + type;
+	};
+	self.update = function () {
+		self.t += 1;
+		// Movement patterns
+		if (self.pattern === 0) {
+			// Straight down
+			self.y += self.speed;
+		} else if (self.pattern === 1) {
+			// Sine wave
+			self.y += self.speed;
+			self.x = self.baseX + Math.sin(self.t / 20) * 180;
+		} else if (self.pattern === 2) {
+			// Zigzag
+			self.y += self.speed;
+			self.x = self.baseX + (self.t % 60 < 30 ? -80 : 80);
+		}
+	};
+	// Flash when hit
+	self.flash = function () {
+		tween(self.asset, {
+			tint: 0xffffff
+		}, {
+			duration: 80,
+			onFinish: function onFinish() {
+				tween(self.asset, {
+					tint: self.type === 1 ? 0xff3b3b : self.type === 2 ? 0xffe14d : 0x7bff7b
+				}, {
+					duration: 120
+				});
+			}
+		});
+	};
+	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.dx = 0;
+	self.dy = 1;
+	self.update = function () {
+		self.x += self.dx * self.speed;
+		self.y += self.dy * self.speed;
+	};
+	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;
+});
+// Player Ship
+var PlayerShip = Container.expand(function () {
+	var self = Container.call(this);
+	var ship = self.attachAsset('playerShip', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.width = ship.width;
+	self.height = ship.height;
+	self.speed = 22;
+	self.shootCooldown = 0;
+	self.powerLevel = 1; // 1: single, 2: double, 3: triple
+	self.invincible = 0; // frames left of invincibility
+	// Flash when hit
+	self.flash = function () {
+		tween(ship, {
+			tint: 0xffff00
+		}, {
+			duration: 100,
+			onFinish: function onFinish() {
+				tween(ship, {
+					tint: 0x33c1ff
+				}, {
+					duration: 200
+				});
+			}
+		});
+	};
+	return self;
+});
+// Powerup
+var Powerup = Container.expand(function () {
+	var self = Container.call(this);
+	var asset = self.attachAsset('powerup', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.type = 1; // 1: power, 2: shield
+	self.update = function () {
+		self.y += 10;
+	};
+	return self;
+});
+
+/**** 
 * Initialize Game
-****/
+****/ 
 var game = new LK.Game({
 	backgroundColor: 0x000000
-});
\ No newline at end of file
+});
+
+/**** 
+* Game Code
+****/ 
+// Music
+// Sounds
+// Powerup
+// Bullets
+// Enemy types
+// Ship (player)
+// Game state variables
+var player = null;
+var playerBullets = [];
+var enemies = [];
+var enemyBullets = [];
+var powerups = [];
+var dragNode = null;
+var lastMoveX = 0;
+var lastMoveY = 0;
+var scoreTxt = null;
+var level = 1;
+var waveTimer = 0;
+var nextPowerupScore = 30;
+var gameOver = false;
+var lastIntersecting = false;
+var invincibleTimer = 0;
+// Set background color
+game.setBackgroundColor(0x0a0a1a);
+// Score display
+scoreTxt = new Text2('0', {
+	size: 120,
+	fill: 0xFFFFFF
+});
+scoreTxt.anchor.set(0.5, 0);
+LK.gui.top.addChild(scoreTxt);
+// Initialize player
+player = new PlayerShip();
+player.x = 2048 / 2;
+player.y = 2732 - 200;
+game.addChild(player);
+// Start music
+LK.playMusic('bgmusic');
+// Touch controls
+game.down = function (x, y, obj) {
+	// Only allow drag if touch is on lower 1/3 of screen
+	if (y > 2732 * 0.6) {
+		dragNode = player;
+		lastMoveX = x;
+		lastMoveY = y;
+	}
+};
+game.up = function (x, y, obj) {
+	dragNode = null;
+};
+function handleMove(x, y, obj) {
+	if (dragNode === player) {
+		// Clamp to screen
+		var minX = player.width / 2 + 20;
+		var maxX = 2048 - player.width / 2 - 20;
+		var minY = 2732 * 0.6;
+		var maxY = 2732 - player.height / 2 - 20;
+		player.x = Math.max(minX, Math.min(maxX, x));
+		player.y = Math.max(minY, Math.min(maxY, y));
+	}
+}
+game.move = handleMove;
+// Fire player bullets
+function firePlayerBullets() {
+	if (player.shootCooldown > 0) return;
+	var b;
+	if (player.powerLevel === 1) {
+		b = new PlayerBullet();
+		b.x = player.x;
+		b.y = player.y - player.height / 2 - 10;
+		playerBullets.push(b);
+		game.addChild(b);
+	} else if (player.powerLevel === 2) {
+		b = new PlayerBullet();
+		b.x = player.x - 32;
+		b.y = player.y - player.height / 2 - 10;
+		playerBullets.push(b);
+		game.addChild(b);
+		b = new PlayerBullet();
+		b.x = player.x + 32;
+		b.y = player.y - player.height / 2 - 10;
+		playerBullets.push(b);
+		game.addChild(b);
+	} else if (player.powerLevel >= 3) {
+		b = new PlayerBullet();
+		b.x = player.x;
+		b.y = player.y - player.height / 2 - 10;
+		playerBullets.push(b);
+		game.addChild(b);
+		b = new PlayerBullet();
+		b.x = player.x - 48;
+		b.y = player.y - player.height / 2 - 10;
+		playerBullets.push(b);
+		game.addChild(b);
+		b = new PlayerBullet();
+		b.x = player.x + 48;
+		b.y = player.y - player.height / 2 - 10;
+		playerBullets.push(b);
+		game.addChild(b);
+	}
+	LK.getSound('shoot').play();
+	player.shootCooldown = 10; // frames
+}
+// Spawn enemy wave
+function spawnWave() {
+	var n = 4 + Math.floor(level * 0.7);
+	var margin = 180;
+	var spacing = (2048 - margin * 2) / (n - 1);
+	var y0 = -100;
+	for (var i = 0; i < n; i++) {
+		var e = new Enemy();
+		// Evolve enemy types and patterns as level increases
+		var type = 1;
+		var pattern = 0;
+		if (level >= 3 && Math.random() < 0.4) type = 2;
+		if (level >= 7 && Math.random() < 0.25) type = 3;
+		if (level >= 2 && Math.random() < 0.3) pattern = 1;
+		if (level >= 5 && Math.random() < 0.2) pattern = 2;
+		e.init(type, pattern);
+		e.x = margin + i * spacing;
+		e.y = y0 - Math.random() * 120;
+		e.baseX = e.x;
+		e.baseY = e.y;
+		enemies.push(e);
+		game.addChild(e);
+	}
+}
+// Spawn powerup
+function spawnPowerup() {
+	var p = new Powerup();
+	p.x = 200 + Math.random() * (2048 - 400);
+	p.y = -60;
+	// Evolve powerup type
+	if (level >= 5 && Math.random() < 0.5) {
+		p.type = 2; // shield
+	} else {
+		p.type = 1; // power
+	}
+	powerups.push(p);
+	game.addChild(p);
+}
+// Main update loop
+game.update = function () {
+	if (gameOver) return;
+	// Player shooting
+	if (player.shootCooldown > 0) player.shootCooldown--;
+	if (LK.ticks % 6 === 0) firePlayerBullets();
+	// Player invincibility
+	if (player.invincible > 0) {
+		player.invincible--;
+		if (player.invincible === 0) {
+			tween(player, {
+				alpha: 1
+			}, {
+				duration: 200
+			});
+		}
+	}
+	// Update player bullets
+	for (var i = playerBullets.length - 1; i >= 0; i--) {
+		var b = playerBullets[i];
+		b.update();
+		if (b.y < -60) {
+			b.destroy();
+			playerBullets.splice(i, 1);
+			continue;
+		}
+		// Collision with enemies
+		for (var j = enemies.length - 1; j >= 0; j--) {
+			var e = enemies[j];
+			if (b.intersects(e)) {
+				e.hp--;
+				e.flash();
+				if (e.hp <= 0) {
+					LK.setScore(LK.getScore() + e.scoreValue);
+					scoreTxt.setText(LK.getScore());
+					LK.getSound('explosion').play();
+					e.destroy();
+					enemies.splice(j, 1);
+				}
+				b.destroy();
+				playerBullets.splice(i, 1);
+				break;
+			}
+		}
+	}
+	// Update enemies
+	for (var i = enemies.length - 1; i >= 0; i--) {
+		var e = enemies[i];
+		e.update();
+		// Enemy shoots
+		if (level >= 2 && LK.ticks % (60 - Math.min(level * 2, 40)) === 0 && Math.random() < 0.5) {
+			var eb = new EnemyBullet();
+			eb.x = e.x;
+			eb.y = e.y + e.height / 2 + 10;
+			// Aim at player
+			var dx = player.x - e.x;
+			var dy = player.y - e.y;
+			var len = Math.sqrt(dx * dx + dy * dy);
+			if (len > 0) {
+				eb.dx = dx / len;
+				eb.dy = dy / len;
+			}
+			enemyBullets.push(eb);
+			game.addChild(eb);
+			LK.getSound('enemyShoot').play();
+		}
+		// Remove if off screen
+		if (e.y > 2732 + 100) {
+			e.destroy();
+			enemies.splice(i, 1);
+		}
+	}
+	// Update enemy bullets
+	for (var i = enemyBullets.length - 1; i >= 0; i--) {
+		var eb = enemyBullets[i];
+		eb.update();
+		if (eb.y > 2732 + 60 || eb.x < -60 || eb.x > 2048 + 60) {
+			eb.destroy();
+			enemyBullets.splice(i, 1);
+			continue;
+		}
+		// Collision with player
+		if (player.invincible === 0 && eb.intersects(player)) {
+			player.flash();
+			player.invincible = 60;
+			tween(player, {
+				alpha: 0.5
+			}, {
+				duration: 100
+			});
+			LK.effects.flashScreen(0xff0000, 400);
+			LK.showGameOver();
+			gameOver = true;
+			return;
+		}
+	}
+	// Update powerups
+	for (var i = powerups.length - 1; i >= 0; i--) {
+		var p = powerups[i];
+		p.update();
+		if (p.y > 2732 + 60) {
+			p.destroy();
+			powerups.splice(i, 1);
+			continue;
+		}
+		// Collision with player
+		if (p.intersects(player)) {
+			LK.getSound('powerup').play();
+			if (p.type === 1) {
+				// Power up: increase powerLevel
+				if (player.powerLevel < 3) player.powerLevel++;
+			} else if (p.type === 2) {
+				// Shield: invincibility
+				player.invincible = 180;
+				tween(player, {
+					alpha: 0.5
+				}, {
+					duration: 100
+				});
+			}
+			p.destroy();
+			powerups.splice(i, 1);
+		}
+	}
+	// Spawn new wave if all enemies gone
+	if (enemies.length === 0 && waveTimer <= 0) {
+		spawnWave();
+		level++;
+		waveTimer = 60;
+	}
+	if (waveTimer > 0) waveTimer--;
+	// Spawn powerup at score milestones
+	if (LK.getScore() >= nextPowerupScore) {
+		spawnPowerup();
+		nextPowerupScore += 40 + Math.floor(level * 10);
+	}
+};
\ No newline at end of file