===================================================================
--- original.js
+++ change.js
@@ -1,6 +1,364 @@
-/****
+/**** 
+* Plugins
+****/ 
+var tween = LK.import("@upit/tween.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.speed = -22;
+	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.speed = 7;
+	self.update = function () {
+		self.y += self.speed;
+	};
+	return self;
+});
+// Survivor class
+var Survivor = Container.expand(function () {
+	var self = Container.call(this);
+	var survivorSprite = self.attachAsset('survivor', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	// For powerup effect
+	self.isPowered = false;
+	self.powerTimer = 0;
+	// For future: add more survivor logic here
+	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
+	});
+	// Movement speed (pixels per frame)
+	self.speed = 4 + Math.random() * 2;
+	// Sway amplitude and frequency for zigzag
+	self.swayAmp = 60 + Math.random() * 80;
+	self.swayFreq = 0.005 + Math.random() * 0.003;
+	self.baseX = 0;
+	self.t = 0;
+	// For tracking last position for offscreen detection
+	self.lastY = undefined;
+	// For tracking intersection with bullets
+	self.lastIntersecting = false;
+	// For tracking intersection with survivor
+	self.lastTouchSurvivor = false;
+	// For powerup drop
+	self.hasDroppedPowerup = false;
+	self.update = function () {
+		self.t += 1;
+		self.y += self.speed;
+		self.x = self.baseX + Math.sin(self.t * self.swayFreq * 60) * self.swayAmp;
+	};
+	return self;
+});
+
+/**** 
 * Initialize Game
-****/
+****/ 
 var game = new LK.Game({
-	backgroundColor: 0x000000
+	backgroundColor: 0x181818
+});
+
+/**** 
+* Game Code
+****/ 
+// Music (not played in MVP as per instructions, but asset is here for future)
+// Sound for zombie hit
+// Sound for powerup
+// Sound for shooting
+// Powerup asset: a magenta ellipse
+// Bullet asset: a yellow box
+// Zombie asset: a green ellipse
+// Survivor (player) asset: a blue box
+// Survivor instance
+var survivor = new Survivor();
+game.addChild(survivor);
+// Place survivor at bottom center, above bottom edge
+survivor.x = 2048 / 2;
+survivor.y = 2732 - 180;
+// Arrays for game objects
+var zombies = [];
+var bullets = [];
+var powerups = [];
+// Score display
+var scoreTxt = new Text2('0', {
+	size: 120,
+	fill: "#fff"
+});
+scoreTxt.anchor.set(0.5, 0);
+LK.gui.top.addChild(scoreTxt);
+// Powerup timer display
+var powerupTxt = new Text2('', {
+	size: 70,
+	fill: 0xFF3FD6
+});
+powerupTxt.anchor.set(0.5, 0);
+LK.gui.top.addChild(powerupTxt);
+powerupTxt.y = 120;
+// Game state
+var dragNode = null;
+var canShoot = true;
+var shootCooldown = 0;
+var shootInterval = 12; // frames between shots
+var zombieSpawnTimer = 0;
+var zombieSpawnInterval = 60; // frames between spawns, will decrease
+var zombieSpeedIncrease = 0;
+var powerupActive = false;
+var powerupTimer = 0;
+var powerupDuration = 360; // frames (6 seconds)
+var lastGameOver = false;
+// Helper: spawn a zombie
+function spawnZombie() {
+	var z = new Zombie();
+	// Random x within screen, but not too close to edge
+	var margin = 120;
+	z.baseX = margin + Math.random() * (2048 - 2 * margin);
+	z.x = z.baseX;
+	z.y = -100;
+	// Increase speed as game progresses
+	z.speed += zombieSpeedIncrease;
+	zombies.push(z);
+	game.addChild(z);
+}
+// Helper: spawn a powerup at (x, y)
+function spawnPowerup(x, y) {
+	var p = new Powerup();
+	p.x = x;
+	p.y = y;
+	powerups.push(p);
+	game.addChild(p);
+}
+// Helper: shoot a bullet
+function shootBullet() {
+	if (!canShoot) return;
+	canShoot = false;
+	shootCooldown = 0;
+	var b = new Bullet();
+	b.x = survivor.x;
+	b.y = survivor.y - 80;
+	bullets.push(b);
+	game.addChild(b);
+	LK.getSound('shoot').play();
+}
+// Dragging logic
+game.down = function (x, y, obj) {
+	// Only allow drag if touch is on lower 1/3 of screen
+	if (y > 2732 * 0.66) {
+		dragNode = survivor;
+	}
+};
+game.up = function (x, y, obj) {
+	dragNode = null;
+};
+function handleMove(x, y, obj) {
+	if (dragNode === survivor) {
+		// Clamp survivor to screen horizontally
+		var halfW = survivor.width / 2;
+		var nx = Math.max(halfW, Math.min(2048 - halfW, x));
+		survivor.x = nx;
+	}
+}
+game.move = handleMove;
+// Tap to shoot logic
+game.tap = function (x, y, obj) {
+	// Only allow tap to shoot if not dragging
+	if (!dragNode) {
+		shootBullet();
+	}
+};
+// For touch devices, simulate tap on quick down/up
+var lastDownTime = 0;
+game.down = function (x, y, obj) {
+	if (y > 2732 * 0.66) {
+		dragNode = survivor;
+		lastDownTime = Date.now();
+	} else {
+		lastDownTime = Date.now();
+	}
+};
+game.up = function (x, y, obj) {
+	if (dragNode === survivor) {
+		dragNode = null;
+	} else {
+		// If quick tap, treat as tap to shoot
+		if (Date.now() - lastDownTime < 250) {
+			shootBullet();
+		}
+	}
+};
+// Main update loop
+game.update = function () {
+	// Handle survivor powerup timer
+	if (powerupActive) {
+		powerupTimer--;
+		if (powerupTimer <= 0) {
+			powerupActive = false;
+			survivor.isPowered = false;
+			powerupTxt.setText('');
+			// Visual: scale back to normal
+			tween(survivor, {
+				scaleX: 1,
+				scaleY: 1
+			}, {
+				duration: 200,
+				easing: tween.easeOut
+			});
+		} else {
+			powerupTxt.setText('POWER! ' + Math.ceil(powerupTimer / 60));
+		}
+	}
+	// Shooting cooldown
+	if (!canShoot) {
+		shootCooldown++;
+		if (shootCooldown >= (powerupActive ? 4 : shootInterval)) {
+			canShoot = true;
+		}
+	}
+	// Spawn zombies
+	zombieSpawnTimer++;
+	if (zombieSpawnTimer >= zombieSpawnInterval) {
+		spawnZombie();
+		zombieSpawnTimer = 0;
+		// Increase difficulty over time
+		if (zombieSpawnInterval > 24) zombieSpawnInterval -= 1;
+		zombieSpeedIncrease += 0.01;
+	}
+	// Update bullets
+	for (var i = bullets.length - 1; i >= 0; i--) {
+		var b = bullets[i];
+		b.update();
+		// Remove if offscreen
+		if (b.y < -100) {
+			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 (b.intersects(z)) {
+				// Hit!
+				LK.getSound('zombiehit').play();
+				// Score
+				LK.setScore(LK.getScore() + 1);
+				scoreTxt.setText(LK.getScore());
+				// Powerup drop chance
+				if (!z.hasDroppedPowerup && Math.random() < 0.08) {
+					spawnPowerup(z.x, z.y);
+					z.hasDroppedPowerup = true;
+				}
+				// Visual: flash zombie
+				LK.effects.flashObject(z, 0xffffff, 200);
+				// Remove both
+				z.destroy();
+				zombies.splice(j, 1);
+				b.destroy();
+				bullets.splice(i, 1);
+				break;
+			}
+		}
+	}
+	// Update zombies
+	for (var i = zombies.length - 1; i >= 0; i--) {
+		var z = zombies[i];
+		z.update();
+		// Remove if offscreen (bottom)
+		if (z.y > 2732 + 100) {
+			z.destroy();
+			zombies.splice(i, 1);
+			continue;
+		}
+		// Check collision with survivor
+		if (z.intersects(survivor)) {
+			if (!lastGameOver) {
+				// Game over
+				LK.effects.flashScreen(0xff0000, 1000);
+				lastGameOver = true;
+				LK.showGameOver();
+				return;
+			}
+		}
+	}
+	// Update powerups
+	for (var i = powerups.length - 1; i >= 0; i--) {
+		var p = powerups[i];
+		p.update();
+		// Remove if offscreen
+		if (p.y > 2732 + 100) {
+			p.destroy();
+			powerups.splice(i, 1);
+			continue;
+		}
+		// Check collision with survivor
+		if (p.intersects(survivor)) {
+			LK.getSound('powerup').play();
+			// Activate powerup: rapid fire
+			powerupActive = true;
+			powerupTimer = powerupDuration;
+			survivor.isPowered = true;
+			// Visual: scale up
+			tween(survivor, {
+				scaleX: 1.3,
+				scaleY: 1.3
+			}, {
+				duration: 200,
+				easing: tween.easeOut
+			});
+			powerupTxt.setText('POWER! ' + Math.ceil(powerupTimer / 60));
+			p.destroy();
+			powerups.splice(i, 1);
+			continue;
+		}
+	}
+};
+// Reset game state on restart
+LK.on('gameStart', function () {
+	// Remove all zombies, bullets, powerups
+	for (var i = 0; i < zombies.length; i++) zombies[i].destroy();
+	for (var i = 0; i < bullets.length; i++) bullets[i].destroy();
+	for (var i = 0; i < powerups.length; i++) powerups[i].destroy();
+	zombies = [];
+	bullets = [];
+	powerups = [];
+	// Reset survivor
+	survivor.x = 2048 / 2;
+	survivor.y = 2732 - 180;
+	survivor.isPowered = false;
+	survivor.scaleX = 1;
+	survivor.scaleY = 1;
+	// Reset timers and state
+	canShoot = true;
+	shootCooldown = 0;
+	zombieSpawnTimer = 0;
+	zombieSpawnInterval = 60;
+	zombieSpeedIncrease = 0;
+	powerupActive = false;
+	powerupTimer = 0;
+	powerupTxt.setText('');
+	lastGameOver = false;
+	LK.setScore(0);
+	scoreTxt.setText('0');
 });
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