===================================================================
--- original.js
+++ change.js
@@ -34,8 +34,9 @@
 		anchorX: 0.5,
 		anchorY: 0.5
 	});
 	self.speed = 2;
+	self.health = 1; // Default health
 	self.update = function () {
 		var dx = player.x - self.x;
 		var dy = player.y - self.y;
 		var magnitude = Math.sqrt(dx * dx + dy * dy);
@@ -43,8 +44,14 @@
 		dy /= magnitude;
 		self.x += dx * self.speed;
 		self.y += dy * self.speed;
 	};
+	self.takeDamage = function (amount) {
+		self.health -= amount;
+		if (self.health <= 0) {
+			self.destroy();
+		}
+	};
 });
 
 /**** 
 * Initialize Game
@@ -55,8 +62,21 @@
 
 /**** 
 * Game Code
 ****/ 
+// Wave system variables
+var currentWave = 1;
+var zombiesPerWave = 20;
+var waveDelay = 3000; // 3 seconds
+var waveTimer = 0;
+var waveMessage = new Text2('', {
+	size: 80,
+	fill: 0xFFFFFF
+});
+waveMessage.anchor.set(0.5, 0);
+LK.gui.top.addChild(waveMessage);
+waveMessage.x = 2048 / 2;
+waveMessage.y = 150;
 var background = game.attachAsset('background', {
 	anchorX: 0,
 	anchorY: 0
 });
@@ -97,8 +117,14 @@
 function spawnZombie() {
 	var zombie = new Zombie();
 	zombie.x = 2048;
 	zombie.y = Math.random() * 2732;
+	// Introduce variations in zombie types
+	if (currentWave > 3 && Math.random() < 0.3) {
+		zombie.speed = 4; // Faster zombie
+	} else if (currentWave > 5 && Math.random() < 0.2) {
+		zombie.health = 2; // Stronger zombie
+	}
 	zombies.push(zombie);
 	game.addChild(zombie);
 }
 // Shooting bullets
@@ -144,19 +170,35 @@
 			if (bullets[k].intersects(zombies[l])) {
 				score += 10;
 				scoreTxt.setText('Score: ' + score);
 				bullets[k].destroy();
-				zombies[l].destroy();
+				zombies[l].takeDamage(1);
+				bullets[k].destroy();
 				bullets.splice(k, 1);
-				zombies.splice(l, 1);
-				LK.getSound('zombieKill').play();
+				if (zombies[l].health <= 0) {
+					zombies.splice(l, 1);
+					LK.getSound('zombieKill').play();
+				}
 				break;
 			}
 		}
 	}
-	// Spawn zombies every 60 ticks
-	if (LK.ticks % 60 === 0) {
-		spawnZombie();
+	// Handle wave system
+	if (zombies.length === 0 && waveTimer <= 0) {
+		// Start new wave
+		waveMessage.setText('Wave ' + currentWave + ': ' + zombiesPerWave + ' Zombies');
+		waveTimer = waveDelay;
+		for (var n = 0; n < zombiesPerWave; n++) {
+			spawnZombie();
+		}
+		currentWave++;
+		zombiesPerWave += 5; // Increase zombies per wave
+		waveDelay = Math.max(1000, waveDelay - 200); // Decrease delay, minimum 1 second
+	} else if (waveTimer > 0) {
+		waveTimer -= 1000 / 60; // Decrease timer by 1/60th of a second
+		if (waveTimer <= 0) {
+			waveMessage.setText('');
+		}
 	}
 };
 // Player controls
 game.down = function (x, y, obj) {