/**** 
* Plugins
****/ 
var tween = LK.import("@upit/tween.v1");

/**** 
* Classes
****/ 
// Bullet fired by soldiers
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletAsset = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 16;
	self.target = null; // Zombie instance
	self.damage = 1;
	self.update = function () {
		if (!self.target || self.target.isDead) {
			self.destroy();
			return;
		}
		// Move towards target
		var dx = self.target.x - self.x;
		var dy = self.target.y - self.y;
		var dist = Math.sqrt(dx * dx + dy * dy);
		if (dist < 32) {
			// Hit!
			self.target.takeDamage(self.damage);
			self.destroy();
			return;
		}
		var step = self.speed;
		self.x += dx / dist * step;
		self.y += dy / dist * step;
	};
	return self;
});
// Gold coin dropped by zombies
var Gold = Container.expand(function () {
	var self = Container.call(this);
	var goldAsset = self.attachAsset('gold', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.value = 1;
	self.life = 180; // 3 seconds
	self.update = function () {
		self.life--;
		if (self.life <= 0) {
			self.destroy();
		}
	};
	return self;
});
// Soldier on a watchtower
var Soldier = Container.expand(function () {
	var self = Container.call(this);
	var soldierAsset = self.attachAsset('soldier', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.level = 1;
	self.fireRate = 60; // frames between shots
	self.fireTimer = 0;
	self.range = 600;
	self.upgradeCost = 5;
	self.parentTower = null;
	self.update = function () {
		if (!self.parentTower) return;
		self.fireTimer--;
		if (self.fireTimer <= 0) {
			// Find nearest zombie in range
			var nearest = null;
			var minDist = self.range;
			for (var i = 0; i < zombies.length; i++) {
				var z = zombies[i];
				if (z.isDead) continue;
				var dx = z.x - self.x;
				var dy = z.y - self.y;
				var dist = Math.sqrt(dx * dx + dy * dy);
				if (dist < minDist) {
					minDist = dist;
					nearest = z;
				}
			}
			if (nearest) {
				// Fire!
				var bullet = new Bullet();
				bullet.x = self.x;
				bullet.y = self.y;
				bullet.target = nearest;
				bullet.damage = self.level;
				bullets.push(bullet);
				game.addChild(bullet);
				LK.getSound('shoot').play();
				self.fireTimer = Math.max(20, self.fireRate - self.level * 8);
			}
		}
	};
	self.upgrade = function () {
		self.level++;
		self.fireRate = Math.max(20, self.fireRate - 8);
		self.upgradeCost += 5;
		// Animate upgrade
		tween(self, {
			scaleX: 1.2,
			scaleY: 1.2
		}, {
			duration: 120,
			onFinish: function onFinish() {
				tween(self, {
					scaleX: 1,
					scaleY: 1
				}, {
					duration: 120
				});
			}
		});
	};
	return self;
});
// Watchtower (can have a soldier)
var Watchtower = Container.expand(function () {
	var self = Container.call(this);
	var towerAsset = self.attachAsset('watchtower', {
		anchorX: 0.5,
		anchorY: 1
	});
	self.soldier = null;
	self.index = 0;
	// For tap detection
	self.down = function (x, y, obj) {
		if (!self.soldier) {
			// Recruit soldier if enough gold (5)
			if (game.gold >= 5) {
				game.gold -= 5;
				var s = new Soldier();
				s.x = self.x;
				s.y = self.y - 80;
				s.parentTower = self;
				self.soldier = s;
				soldiers.push(s);
				game.addChild(s);
				updateGoldText();
				// Animate
				tween(s, {
					alpha: 0
				}, {
					duration: 0,
					onFinish: function onFinish() {
						tween(s, {
							alpha: 1
						}, {
							duration: 200
						});
					}
				});
			}
		} else {
			// Upgrade soldier
			if (game.gold >= self.soldier.upgradeCost) {
				game.gold -= self.soldier.upgradeCost;
				self.soldier.upgrade();
				updateGoldText();
			}
		}
	};
	return self;
});
// Zombie enemy
var Zombie = Container.expand(function () {
	var self = Container.call(this);
	var zombieAsset = self.attachAsset('zombie', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.maxHp = 2;
	self.hp = self.maxHp;
	self.speed = 2 + Math.random() * 1.5;
	self.isDead = false;
	self.targetX = 0;
	self.targetY = 0;
	self.takeDamage = function (dmg) {
		if (self.isDead) return;
		self.hp -= dmg;
		if (self.hp <= 0) {
			self.die();
		} else {
			// Flash red
			tween(self, {
				tint: 0xFF0000
			}, {
				duration: 80,
				onFinish: function onFinish() {
					tween(self, {
						tint: 0x4CAF50
					}, {
						duration: 120
					});
				}
			});
		}
	};
	self.die = function () {
		if (self.isDead) return;
		self.isDead = true;
		LK.getSound('zombieDie').play();
		// Drop gold (now only collectable by tapping)
		var gold = new Gold();
		gold.x = self.x;
		gold.y = self.y;
		golds.push(gold);
		game.addChild(gold);
		// Animate fade out
		tween(self, {
			alpha: 0
		}, {
			duration: 200,
			onFinish: function onFinish() {
				self.destroy();
			}
		});
	};
	self.update = function () {
		if (self.isDead) return;
		var dx = self.targetX - self.x;
		var dy = self.targetY - self.y;
		var dist = Math.sqrt(dx * dx + dy * dy);
		if (dist < 30) {
			// Reached gate
			self.isDead = true;
			self.destroy();
			// Damage gate
			game.gateHp--;
			LK.effects.flashObject(game.castleGate, 0xFF0000, 400);
			if (game.gateHp <= 0) {
				LK.effects.flashScreen(0xFF0000, 1000);
				LK.showGameOver();
			}
			return;
		}
		var step = self.speed;
		self.x += dx / dist * step;
		self.y += dy / dist * step;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x222233
});

/**** 
* Game Code
****/ 
// Play music
// Castle gate (center bottom)
// Watchtower base
// Soldier
// Zombie
// Bullet
// Gold coin
// Sound for shooting
// Sound for collecting gold
// Sound for zombie death
// Music
LK.playMusic('castleTheme');
// Game variables
var zombies = [];
var bullets = [];
var golds = [];
var soldiers = [];
var towers = [];
game.gateHp = 5;
game.gold = 10;
game.wave = 1;
game.waveTimer = 0;
// Castle gate
game.castleGate = LK.getAsset('castleGate', {
	anchorX: 0.5,
	anchorY: 1,
	x: 1024,
	y: 2000 // Move gate up to visually center it among towers
});
game.addChild(game.castleGate);
// Watchtower positions (left, center, right, top-left, top-right)
var towerPositions = [{
	x: 400,
	y: 1800
}, {
	x: 1024,
	y: 1700
}, {
	x: 1648,
	y: 1800
}, {
	x: 700,
	y: 1200
}, {
	x: 1348,
	y: 1200
}];
for (var i = 0; i < towerPositions.length; i++) {
	var pos = towerPositions[i];
	var tower = new Watchtower();
	tower.x = pos.x;
	tower.y = pos.y;
	tower.index = i;
	towers.push(tower);
	game.addChild(tower);
}
// GUI: Gold display
var goldTxt = new Text2('Gold: 10', {
	size: 90,
	fill: 0xFFD700
});
goldTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(goldTxt);
// GUI: Gate HP display
var hpTxt = new Text2('Gate: 5', {
	size: 90,
	fill: 0xFFFFFF
});
hpTxt.anchor.set(0.5, 0);
LK.gui.topRight.addChild(hpTxt);
// GUI: Wave display
var waveTxt = new Text2('Wave: 1', {
	size: 80,
	fill: 0x00BFFF
});
waveTxt.anchor.set(0.5, 0);
LK.gui.bottom.addChild(waveTxt);
// --- Zoom Controls ---
var zoomLevel = 1;
var minZoom = 0.5;
var maxZoom = 2.0;
var zoomStep = 0.2;
// Zoom In Button
var zoomInBtn = new Text2('+', {
	size: 120,
	fill: 0xFFFFFF
});
zoomInBtn.anchor.set(0.5, 0.5);
zoomInBtn.x = 1800;
zoomInBtn.y = 200;
zoomInBtn.interactive = true;
zoomInBtn.buttonMode = true;
zoomInBtn.down = function (x, y, obj) {
	if (zoomLevel < maxZoom) {
		zoomLevel += zoomStep;
		if (zoomLevel > maxZoom) zoomLevel = maxZoom;
		game.scaleX = zoomLevel;
		game.scaleY = zoomLevel;
	}
};
LK.gui.right.addChild(zoomInBtn);
// Zoom Out Button
var zoomOutBtn = new Text2('-', {
	size: 120,
	fill: 0xFFFFFF
});
zoomOutBtn.anchor.set(0.5, 0.5);
zoomOutBtn.x = 1800;
zoomOutBtn.y = 350;
zoomOutBtn.interactive = true;
zoomOutBtn.buttonMode = true;
zoomOutBtn.down = function (x, y, obj) {
	if (zoomLevel > minZoom) {
		zoomLevel -= zoomStep;
		if (zoomLevel < minZoom) zoomLevel = minZoom;
		game.scaleX = zoomLevel;
		game.scaleY = zoomLevel;
	}
};
LK.gui.right.addChild(zoomOutBtn);
function updateGoldText() {
	goldTxt.setText('Gold: ' + game.gold);
}
function updateHpText() {
	hpTxt.setText('Gate: ' + game.gateHp);
}
function updateWaveText() {
	waveTxt.setText('Wave: ' + game.wave);
}
// Handle collecting gold and buying soldiers/upgrades
game.down = function (x, y, obj) {
	// Check if gold was tapped
	for (var i = golds.length - 1; i >= 0; i--) {
		var g = golds[i];
		var dx = g.x - x;
		var dy = g.y - y;
		if (dx * dx + dy * dy < 900) {
			// Collect
			LK.getSound('coin').play();
			game.gold += g.value;
			updateGoldText();
			g.destroy();
			golds.splice(i, 1);
			return;
		}
	}
	// Check if a tower was tapped
	for (var j = 0; j < towers.length; j++) {
		var t = towers[j];
		var tx = t.x,
			ty = t.y;
		if (x > tx - 60 && x < tx + 60 && y > ty - 220 && y < ty) {
			t.down(x, y, obj);
			return;
		}
	}
};
// Main update loop
game.update = function () {
	// Update gate HP and gold
	updateHpText();
	// Update all zombies
	for (var i = zombies.length - 1; i >= 0; i--) {
		var z = zombies[i];
		z.update();
		if (z.isDead && z.alpha === 0) {
			z.destroy();
			zombies.splice(i, 1);
		}
	}
	// Update all bullets
	for (var i = bullets.length - 1; i >= 0; i--) {
		var b = bullets[i];
		b.update();
		if (b.destroyed) {
			bullets.splice(i, 1);
		}
	}
	// Update all golds
	for (var i = golds.length - 1; i >= 0; i--) {
		var g = golds[i];
		g.update();
		if (g.life <= 0 || g.destroyed) {
			g.destroy();
			golds.splice(i, 1);
		}
	}
	// Update all soldiers
	for (var i = 0; i < soldiers.length; i++) {
		soldiers[i].update();
	}
	// Spawn new wave every 180 ticks (3 seconds)
	game.waveTimer++;
	if (game.waveTimer >= 180) {
		game.waveTimer = 0;
		spawnWave();
	}
};
function spawnWave() {
	var n = 2 + Math.floor(game.wave * 0.7);
	for (var i = 0; i < n; i++) {
		var z = new Zombie();
		// Spawn from random edge
		var edge = Math.floor(Math.random() * 4);
		var zx, zy;
		if (edge === 0) {
			// left
			zx = -60;
			zy = 1000 + Math.random() * 1200;
		} else if (edge === 1) {
			// right
			zx = 2048 + 60;
			zy = 1000 + Math.random() * 1200;
		} else if (edge === 2) {
			// top
			zx = 400 + Math.random() * 1200;
			zy = -80;
		} else {
			// bottom (rare)
			zx = 400 + Math.random() * 1200;
			zy = 2732 + 80;
		}
		z.x = zx;
		z.y = zy;
		// Gate is at the middle of the castle (centered among towers)
		z.targetX = 1024;
		z.targetY = 2000;
		// Decrease zombie speed (slower base, slower scaling)
		z.maxHp = 2 + Math.floor(game.wave / 2);
		z.hp = z.maxHp;
		z.speed = 1 + Math.random() * 0.7 + game.wave * 0.07;
		zombies.push(z);
		game.addChild(z);
	}
	game.wave++;
	updateWaveText();
}

===================================================================
--- original.js
+++ change.js
@@ -257,19 +257,19 @@
 
 /**** 
 * Game Code
 ****/ 
-// Music
-// Sound for zombie death
-// Sound for collecting gold
-// Sound for shooting
-// Gold coin
-// Bullet
-// Zombie
-// Soldier
-// Watchtower base
-// Castle gate (center bottom)
 // Play music
+// Castle gate (center bottom)
+// Watchtower base
+// Soldier
+// Zombie
+// Bullet
+// Gold coin
+// Sound for shooting
+// Sound for collecting gold
+// Sound for zombie death
+// Music
 LK.playMusic('castleTheme');
 // Game variables
 var zombies = [];
 var bullets = [];
@@ -334,8 +334,51 @@
 	fill: 0x00BFFF
 });
 waveTxt.anchor.set(0.5, 0);
 LK.gui.bottom.addChild(waveTxt);
+// --- Zoom Controls ---
+var zoomLevel = 1;
+var minZoom = 0.5;
+var maxZoom = 2.0;
+var zoomStep = 0.2;
+// Zoom In Button
+var zoomInBtn = new Text2('+', {
+	size: 120,
+	fill: 0xFFFFFF
+});
+zoomInBtn.anchor.set(0.5, 0.5);
+zoomInBtn.x = 1800;
+zoomInBtn.y = 200;
+zoomInBtn.interactive = true;
+zoomInBtn.buttonMode = true;
+zoomInBtn.down = function (x, y, obj) {
+	if (zoomLevel < maxZoom) {
+		zoomLevel += zoomStep;
+		if (zoomLevel > maxZoom) zoomLevel = maxZoom;
+		game.scaleX = zoomLevel;
+		game.scaleY = zoomLevel;
+	}
+};
+LK.gui.right.addChild(zoomInBtn);
+// Zoom Out Button
+var zoomOutBtn = new Text2('-', {
+	size: 120,
+	fill: 0xFFFFFF
+});
+zoomOutBtn.anchor.set(0.5, 0.5);
+zoomOutBtn.x = 1800;
+zoomOutBtn.y = 350;
+zoomOutBtn.interactive = true;
+zoomOutBtn.buttonMode = true;
+zoomOutBtn.down = function (x, y, obj) {
+	if (zoomLevel > minZoom) {
+		zoomLevel -= zoomStep;
+		if (zoomLevel < minZoom) zoomLevel = minZoom;
+		game.scaleX = zoomLevel;
+		game.scaleY = zoomLevel;
+	}
+};
+LK.gui.right.addChild(zoomOutBtn);
 function updateGoldText() {
 	goldTxt.setText('Gold: ' + game.gold);
 }
 function updateHpText() {