===================================================================
--- original.js
+++ change.js
@@ -1,6 +1,327 @@
-/****
+/**** 
+* Plugins
+****/ 
+var tween = LK.import("@upit/tween.v1");
+var storage = LK.import("@upit/storage.v1");
+
+/**** 
+* Classes
+****/ 
+// Bullet class
+var Bullet = Container.expand(function () {
+	var self = Container.call(this);
+	var bulletSprite = self.attachAsset('bullet', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.radius = bulletSprite.width / 2;
+	self.vx = 0;
+	self.vy = 0;
+	self.lifetime = 60; // frames
+	self.update = function () {
+		self.x += self.vx;
+		self.y += self.vy;
+		self.lifetime--;
+	};
+	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.radius = heroSprite.width / 2;
+	self.speed = 18; // pixels per move
+	self.lastShotTick = 0;
+	self.shootCooldown = 18; // frames between shots
+	self.update = function () {};
+	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.radius = powerupSprite.width / 2;
+	self.type = 'rapid'; // only one type for MVP
+	self.update = function () {};
+	return self;
+});
+// Zombie class
+var Zombie = Container.expand(function () {
+	var self = Container.call(this);
+	var zombieSprite = self.attachAsset('zombie', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.radius = zombieSprite.width / 2;
+	self.speed = 3 + Math.random() * 2; // will be increased by wave
+	self.target = null; // set to hero
+	self.update = function () {
+		if (!self.target) return;
+		var dx = self.target.x - self.x;
+		var dy = self.target.y - self.y;
+		var dist = Math.sqrt(dx * dx + dy * dy);
+		if (dist > 0) {
+			self.x += self.speed * dx / dist;
+			self.y += self.speed * dy / dist;
+		}
+	};
+	return self;
+});
+
+/**** 
 * Initialize Game
-****/
+****/ 
 var game = new LK.Game({
-	backgroundColor: 0x000000
+	backgroundColor: 0x181818
+});
+
+/**** 
+* Game Code
+****/ 
+// Music
+// Sound effects
+// Powerup: blue ellipse
+// Bullet: yellow box
+// Zombie: green ellipse
+// Hero: red box
+// Game area
+var GAME_W = 2048;
+var GAME_H = 2732;
+// State
+var hero = null;
+var zombies = [];
+var bullets = [];
+var powerups = [];
+var dragNode = null;
+var lastIntersecting = false;
+var score = 0;
+var highScore = storage.highScore || 0;
+var wave = 1;
+var ticksSinceStart = 0;
+var zombieSpawnTick = 0;
+var zombieSpawnInterval = 90; // frames
+var rapidFireTicks = 0;
+// Score text
+var scoreTxt = new Text2('0', {
+	size: 120,
+	fill: "#fff"
+});
+scoreTxt.anchor.set(0.5, 0);
+LK.gui.top.addChild(scoreTxt);
+// High score text
+var highScoreTxt = new Text2('Best: ' + highScore, {
+	size: 60,
+	fill: "#fff"
+});
+highScoreTxt.anchor.set(0.5, 0);
+highScoreTxt.y = 120;
+LK.gui.top.addChild(highScoreTxt);
+// Powerup text
+var powerupTxt = new Text2('', {
+	size: 70,
+	fill: 0x3B7DD8
+});
+powerupTxt.anchor.set(0.5, 0);
+powerupTxt.y = 200;
+LK.gui.top.addChild(powerupTxt);
+// Spawn hero in center
+hero = new Hero();
+hero.x = GAME_W / 2;
+hero.y = GAME_H / 2;
+game.addChild(hero);
+// Helper: spawn zombie at random edge
+function spawnZombie() {
+	var z = new Zombie();
+	// Pick edge: 0=top,1=bottom,2=left,3=right
+	var edge = Math.floor(Math.random() * 4);
+	var margin = 80;
+	if (edge === 0) {
+		// top
+		z.x = margin + Math.random() * (GAME_W - 2 * margin);
+		z.y = -z.radius;
+	} else if (edge === 1) {
+		// bottom
+		z.x = margin + Math.random() * (GAME_W - 2 * margin);
+		z.y = GAME_H + z.radius;
+	} else if (edge === 2) {
+		// left
+		z.x = -z.radius;
+		z.y = margin + Math.random() * (GAME_H - 2 * margin);
+	} else {
+		// right
+		z.x = GAME_W + z.radius;
+		z.y = margin + Math.random() * (GAME_H - 2 * margin);
+	}
+	// Increase speed with wave
+	z.speed += (wave - 1) * 0.5;
+	z.target = hero;
+	zombies.push(z);
+	game.addChild(z);
+}
+// Helper: spawn powerup
+function spawnPowerup() {
+	var p = new Powerup();
+	p.x = 200 + Math.random() * (GAME_W - 400);
+	p.y = 300 + Math.random() * (GAME_H - 600);
+	powerups.push(p);
+	game.addChild(p);
+}
+// Helper: shoot bullet towards (tx,ty)
+function shootBullet(tx, ty) {
+	if (LK.ticks - hero.lastShotTick < (rapidFireTicks > 0 ? 6 : hero.shootCooldown)) return;
+	var b = new Bullet();
+	b.x = hero.x;
+	b.y = hero.y;
+	var dx = tx - hero.x;
+	var dy = ty - hero.y;
+	var dist = Math.sqrt(dx * dx + dy * dy);
+	var speed = 38;
+	b.vx = speed * dx / dist;
+	b.vy = speed * dy / dist;
+	bullets.push(b);
+	game.addChild(b);
+	hero.lastShotTick = LK.ticks;
+	LK.getSound('shoot').play();
+}
+// Helper: distance between two objects
+function dist2(a, b) {
+	var dx = a.x - b.x;
+	var dy = a.y - b.y;
+	return Math.sqrt(dx * dx + dy * dy);
+}
+// Dragging
+function handleMove(x, y, obj) {
+	if (dragNode) {
+		// Clamp hero inside game area
+		var r = hero.radius;
+		dragNode.x = Math.max(r, Math.min(GAME_W - r, x));
+		dragNode.y = Math.max(r, Math.min(GAME_H - r, y));
+	}
+}
+game.move = handleMove;
+game.down = function (x, y, obj) {
+	// Only drag if touch is on hero
+	if (dist2({
+		x: x,
+		y: y
+	}, hero) <= hero.radius * 1.2) {
+		dragNode = hero;
+	}
+};
+game.up = function (x, y, obj) {
+	dragNode = null;
+	// Shoot bullet towards release point if not dragging
+	if (dist2({
+		x: x,
+		y: y
+	}, hero) > hero.radius * 1.2) {
+		shootBullet(x, y);
+	}
+};
+// Main update loop
+game.update = function () {
+	ticksSinceStart++;
+	// Increase wave every 900 ticks (~15s)
+	if (ticksSinceStart % 900 === 0) {
+		wave++;
+		if (zombieSpawnInterval > 30) zombieSpawnInterval -= 8;
+	}
+	// Spawn zombies
+	if (LK.ticks - zombieSpawnTick > zombieSpawnInterval) {
+		spawnZombie();
+		zombieSpawnTick = LK.ticks;
+	}
+	// Maybe spawn powerup
+	if (powerups.length === 0 && Math.random() < 0.002) {
+		spawnPowerup();
+	}
+	// Update hero (nothing for now)
+	hero.update();
+	// Update zombies
+	for (var i = zombies.length - 1; i >= 0; i--) {
+		var z = zombies[i];
+		z.update();
+		// Check collision with hero
+		if (dist2(z, hero) < z.radius + hero.radius - 10) {
+			LK.effects.flashScreen(0xff0000, 1000);
+			if (score > highScore) {
+				storage.highScore = score;
+			}
+			LK.showGameOver();
+			return;
+		}
+	}
+	// Update bullets
+	for (var i = bullets.length - 1; i >= 0; i--) {
+		var b = bullets[i];
+		b.update();
+		// Remove if out of bounds or expired
+		if (b.x < -100 || b.x > GAME_W + 100 || b.y < -100 || b.y > GAME_H + 100 || b.lifetime <= 0) {
+			b.destroy();
+			bullets.splice(i, 1);
+			continue;
+		}
+		// Check collision with zombies
+		for (var j = zombies.length - 1; j >= 0; j--) {
+			var z = zombies[j];
+			if (dist2(b, z) < b.radius + z.radius - 10) {
+				// Kill zombie
+				LK.getSound('zombie_die').play();
+				score++;
+				scoreTxt.setText(score);
+				if (score > highScore) {
+					highScore = score;
+					highScoreTxt.setText('Best: ' + highScore);
+					storage.highScore = highScore;
+				}
+				// Flash zombie
+				LK.effects.flashObject(z, 0xffffff, 200);
+				z.destroy();
+				zombies.splice(j, 1);
+				b.destroy();
+				bullets.splice(i, 1);
+				break;
+			}
+		}
+	}
+	// Update powerups
+	for (var i = powerups.length - 1; i >= 0; i--) {
+		var p = powerups[i];
+		// Check collision with hero
+		if (dist2(p, hero) < p.radius + hero.radius - 10) {
+			LK.getSound('powerup').play();
+			rapidFireTicks = 360; // 6 seconds
+			powerupTxt.setText('Rapid Fire!');
+			LK.effects.flashObject(hero, 0x3b7dd8, 400);
+			p.destroy();
+			powerups.splice(i, 1);
+		}
+	}
+	// Powerup timer
+	if (rapidFireTicks > 0) {
+		rapidFireTicks--;
+		if (rapidFireTicks === 0) {
+			powerupTxt.setText('');
+		}
+	}
+	// Update powerup text alpha for effect
+	if (rapidFireTicks > 0) {
+		powerupTxt.alpha = 0.7 + 0.3 * Math.sin(LK.ticks / 6);
+	} else {
+		powerupTxt.alpha = 1;
+	}
+};
+// Start music
+LK.playMusic('bgmusic', {
+	fade: {
+		start: 0,
+		end: 0.7,
+		duration: 1200
+	}
 });
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