===================================================================
--- original.js
+++ change.js
@@ -1,6 +1,330 @@
-/****
+/**** 
+* Plugins
+****/ 
+var tween = LK.import("@upit/tween.v1");
+
+/**** 
+* Classes
+****/ 
+// Enemy class
+var Enemy = Container.expand(function () {
+	var self = Container.call(this);
+	var enemySprite = self.attachAsset('enemy', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.width = enemySprite.width;
+	self.height = enemySprite.height;
+	self.speed = 6 + Math.random() * 3;
+	self.shootTimer = 60 + Math.floor(Math.random() * 60);
+	self.hp = 1;
+	// Update
+	self.update = function () {
+		self.y += self.speed;
+		self.shootTimer--;
+		if (self.shootTimer <= 0) {
+			self.shoot();
+			self.shootTimer = 90 + Math.floor(Math.random() * 60);
+		}
+	};
+	// Shoot
+	self.shoot = function () {
+		var bullet = new EnemyBullet();
+		bullet.x = self.x;
+		bullet.y = self.y + self.height / 2 + bullet.height / 2;
+		enemyBullets.push(bullet);
+		game.addChild(bullet);
+	};
+	return self;
+});
+// Enemy bullet class
+var EnemyBullet = Container.expand(function () {
+	var self = Container.call(this);
+	var bulletSprite = self.attachAsset('enemyBullet', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.width = bulletSprite.width;
+	self.height = bulletSprite.height;
+	self.speed = 18;
+	self.update = function () {
+		self.y += self.speed;
+	};
+	return self;
+});
+// Hero class
+var Hero = Container.expand(function () {
+	var self = Container.call(this);
+	var heroSprite = self.attachAsset('hero', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.width = heroSprite.width;
+	self.height = heroSprite.height;
+	self.shootCooldown = 0;
+	self.poweredUp = false;
+	self.powerupTimer = 0;
+	// Shoot method
+	self.shoot = function () {
+		if (self.shootCooldown > 0) return;
+		var bullet = new HeroBullet();
+		bullet.x = self.x;
+		bullet.y = self.y - self.height / 2 - bullet.height / 2;
+		heroBullets.push(bullet);
+		game.addChild(bullet);
+		LK.getSound('shoot').play();
+		self.shootCooldown = self.poweredUp ? 10 : 20; // Faster shooting if powered up
+	};
+	// Powerup method
+	self.activatePowerup = function () {
+		self.poweredUp = true;
+		self.powerupTimer = 300; // 5 seconds at 60fps
+		tween(self, {
+			scaleX: 1.3,
+			scaleY: 1.3
+		}, {
+			duration: 200,
+			easing: tween.elasticOut
+		});
+	};
+	// Remove powerup
+	self.deactivatePowerup = function () {
+		self.poweredUp = false;
+		tween(self, {
+			scaleX: 1,
+			scaleY: 1
+		}, {
+			duration: 200,
+			easing: tween.elasticIn
+		});
+	};
+	// Update
+	self.update = function () {
+		if (self.shootCooldown > 0) self.shootCooldown--;
+		if (self.poweredUp) {
+			self.powerupTimer--;
+			if (self.powerupTimer <= 0) {
+				self.deactivatePowerup();
+			}
+		}
+	};
+	return self;
+});
+// Hero bullet class
+var HeroBullet = Container.expand(function () {
+	var self = Container.call(this);
+	var bulletSprite = self.attachAsset('heroBullet', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.width = bulletSprite.width;
+	self.height = bulletSprite.height;
+	self.speed = -28;
+	self.update = function () {
+		self.y += self.speed;
+	};
+	return self;
+});
+// Powerup class
+var Powerup = Container.expand(function () {
+	var self = Container.call(this);
+	var powerupSprite = self.attachAsset('powerup', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.width = powerupSprite.width;
+	self.height = powerupSprite.height;
+	self.speed = 10;
+	self.update = function () {
+		self.y += self.speed;
+	};
+	return self;
+});
+
+/**** 
 * Initialize Game
-****/
+****/ 
 var game = new LK.Game({
-	backgroundColor: 0x000000
-});
\ No newline at end of file
+	backgroundColor: 0x222a36
+});
+
+/**** 
+* Game Code
+****/ 
+// Music
+// Sound effects
+// Powerup: green ellipse
+// Hero bullet: yellow box
+// Enemy bullet: orange box
+// Enemy asset: red ellipse
+// Hero asset: blue box
+// Play music
+LK.playMusic('battlefieldMusic');
+// Score
+var score = 0;
+var scoreTxt = new Text2('0', {
+	size: 120,
+	fill: "#fff"
+});
+scoreTxt.anchor.set(0.5, 0);
+LK.gui.top.addChild(scoreTxt);
+// Hero instance
+var hero = new Hero();
+game.addChild(hero);
+hero.x = 2048 / 2;
+hero.y = 2732 - 350;
+// Arrays for game objects
+var enemies = [];
+var heroBullets = [];
+var enemyBullets = [];
+var powerups = [];
+// Dragging
+var dragNode = null;
+// Difficulty
+var spawnTimer = 0;
+var spawnInterval = 60;
+var difficultyTimer = 0;
+// Powerup spawn
+var powerupTimer = 600;
+// Move handler
+function handleMove(x, y, obj) {
+	if (dragNode) {
+		// Clamp hero inside game area, avoid top 100px and bottom 100px
+		var minX = hero.width / 2;
+		var maxX = 2048 - hero.width / 2;
+		var minY = 100 + hero.height / 2;
+		var maxY = 2732 - hero.height / 2 - 100;
+		hero.x = Math.max(minX, Math.min(maxX, x));
+		hero.y = Math.max(minY, Math.min(maxY, y));
+	}
+}
+game.move = handleMove;
+game.down = function (x, y, obj) {
+	// Only start drag if touch is on hero
+	var dx = x - hero.x;
+	var dy = y - hero.y;
+	if (dx * dx + dy * dy < hero.width / 2 * (hero.width / 2)) {
+		dragNode = hero;
+		handleMove(x, y, obj);
+	}
+};
+game.up = function (x, y, obj) {
+	dragNode = null;
+};
+// Main update loop
+game.update = function () {
+	// Hero update
+	hero.update();
+	// Hero auto-shoot
+	if (LK.ticks % (hero.poweredUp ? 6 : 12) === 0) {
+		hero.shoot();
+	}
+	// Spawn enemies
+	spawnTimer--;
+	if (spawnTimer <= 0) {
+		var enemy = new Enemy();
+		var margin = 120;
+		enemy.x = margin + Math.random() * (2048 - 2 * margin);
+		enemy.y = -enemy.height / 2;
+		enemies.push(enemy);
+		game.addChild(enemy);
+		spawnTimer = spawnInterval;
+	}
+	// Increase difficulty over time
+	difficultyTimer++;
+	if (difficultyTimer % 600 === 0 && spawnInterval > 20) {
+		spawnInterval -= 5;
+	}
+	// Powerup spawn
+	powerupTimer--;
+	if (powerupTimer <= 0) {
+		var powerup = new Powerup();
+		powerup.x = 200 + Math.random() * (2048 - 400);
+		powerup.y = -powerup.height / 2;
+		powerups.push(powerup);
+		game.addChild(powerup);
+		powerupTimer = 900 + Math.floor(Math.random() * 600);
+	}
+	// Update and cleanup hero bullets
+	for (var i = heroBullets.length - 1; i >= 0; i--) {
+		var b = heroBullets[i];
+		b.update();
+		if (b.y < -b.height / 2) {
+			b.destroy();
+			heroBullets.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--;
+				if (e.hp <= 0) {
+					LK.getSound('enemyDown').play();
+					score += 10;
+					scoreTxt.setText(score);
+					e.destroy();
+					enemies.splice(j, 1);
+				}
+				b.destroy();
+				heroBullets.splice(i, 1);
+				break;
+			}
+		}
+	}
+	// Update and cleanup enemy bullets
+	for (var i = enemyBullets.length - 1; i >= 0; i--) {
+		var eb = enemyBullets[i];
+		eb.update();
+		if (eb.y > 2732 + eb.height / 2) {
+			eb.destroy();
+			enemyBullets.splice(i, 1);
+			continue;
+		}
+		// Collision with hero
+		if (eb.intersects(hero)) {
+			LK.effects.flashScreen(0xff0000, 800);
+			LK.showGameOver();
+			return;
+		}
+	}
+	// Update and cleanup enemies
+	for (var i = enemies.length - 1; i >= 0; i--) {
+		var e = enemies[i];
+		e.update();
+		if (e.y > 2732 + e.height / 2) {
+			e.destroy();
+			enemies.splice(i, 1);
+			continue;
+		}
+		// Collision with hero
+		if (e.intersects(hero)) {
+			LK.effects.flashScreen(0xff0000, 800);
+			LK.showGameOver();
+			return;
+		}
+	}
+	// Update and cleanup powerups
+	for (var i = powerups.length - 1; i >= 0; i--) {
+		var p = powerups[i];
+		p.update();
+		if (p.y > 2732 + p.height / 2) {
+			p.destroy();
+			powerups.splice(i, 1);
+			continue;
+		}
+		// Collision with hero
+		if (p.intersects(hero)) {
+			LK.getSound('powerup').play();
+			hero.activatePowerup();
+			p.destroy();
+			powerups.splice(i, 1);
+			continue;
+		}
+	}
+	// Win condition: score 500
+	if (score >= 500) {
+		LK.showYouWin();
+		return;
+	}
+};
\ No newline at end of file