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

/**** 
* Classes
****/ 
// Bullet class
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGfx = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.radius = bulletGfx.width / 2;
	self.speed = 32; // Fast bullet
	self.vx = 0;
	self.vy = 0;
	// Set direction
	self.setDirection = function (dx, dy) {
		var len = Math.sqrt(dx * dx + dy * dy);
		if (len > 0) {
			self.vx = dx / len * self.speed;
			self.vy = dy / len * self.speed;
		}
	};
	self.update = function () {
		self.x += self.vx;
		self.y += self.vy;
	};
	return self;
});
// Hero class
var Hero = Container.expand(function () {
	var self = Container.call(this);
	var heroGfx = self.attachAsset('hero', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Add a gun to hero's hand
	// Use the new blue gun asset, positioned to the right hand
	var gunGfx = self.attachAsset('bluegun', {
		anchorX: 0.2,
		anchorY: 0.5,
		scaleX: 1.2,
		scaleY: 0.6,
		x: heroGfx.width * 0.38,
		// offset to right hand
		y: 0
	});
	// Track gun rotation
	self.gunGfx = gunGfx;
	self.gunAngle = 0;
	// For future upgrades: health, weapon, etc.
	self.radius = heroGfx.width / 2;
	return self;
});
// Zombie class
var Zombie = Container.expand(function () {
	var self = Container.call(this);
	var zombieGfx = self.attachAsset('zombie', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.radius = zombieGfx.width / 2;
	// Speed will be set on spawn
	self.speed = 2 + Math.random() * 1.5; // Slight randomization
	// Direction vector
	self.vx = 0;
	self.vy = 0;
	// Set direction towards hero
	self.setDirection = function (targetX, targetY) {
		var dx = targetX - self.x;
		var dy = targetY - self.y;
		var len = Math.sqrt(dx * dx + dy * dy);
		if (len > 0) {
			self.vx = dx / len * self.speed;
			self.vy = dy / len * self.speed;
		}
	};
	// Move towards direction
	self.update = function () {
		self.x += self.vx;
		self.y += self.vy;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x181818
});

/**** 
* Game Code
****/ 
// New blue gun asset
// Game area
// Hero asset: red box
// Zombie asset: green ellipse
// Bullet asset: yellow box
// Sound for shooting
var GAME_W = 2048;
var GAME_H = 2732;
// Hero setup
var hero = new Hero();
hero.x = GAME_W / 2;
hero.y = GAME_H / 2;
game.addChild(hero);
// Bullets and zombies arrays
var bullets = [];
var zombies = [];
// Score
var score = 0;
var scoreTxt = new Text2('0', {
	size: 120,
	fill: "#fff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Dragging
var dragNode = null;
// Touch/move controls
function handleMove(x, y, obj) {
	// Drag hero
	if (dragNode === hero) {
		// Clamp hero inside game area, avoid top left 100x100
		var minX = hero.radius + 100;
		var maxX = GAME_W - hero.radius;
		var minY = hero.radius;
		var maxY = GAME_H - hero.radius;
		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 drag if touch is on hero
	var dx = x - hero.x;
	var dy = y - hero.y;
	if (dx * dx + dy * dy <= hero.radius * hero.radius) {
		dragNode = hero;
		handleMove(x, y, obj);
	}
};
game.up = function (x, y, obj) {
	dragNode = null;
};
// Shooting: tap anywhere not on hero to shoot
game.tap = function (x, y, obj) {
	// Don't shoot if tap is on hero
	var dx = x - hero.x;
	var dy = y - hero.y;
	if (dx * dx + dy * dy <= hero.radius * hero.radius) return;
	// Create bullet
	var bullet = new Bullet();
	bullet.x = hero.x;
	bullet.y = hero.y;
	bullet.setDirection(dx, dy);
	bullets.push(bullet);
	game.addChild(bullet);
	LK.getSound('shoot').play();
	// Rotate gun towards shot direction
	if (typeof hero.gunGfx !== "undefined") {
		hero.gunGfx.rotation = Math.atan2(dy, dx);
	}
};
game.down = function (x, y, obj) {
	// Drag or shoot
	var dx = x - hero.x;
	var dy = y - hero.y;
	if (dx * dx + dy * dy <= hero.radius * hero.radius) {
		dragNode = hero;
		handleMove(x, y, obj);
	} else {
		// Shoot
		var bullet = new Bullet();
		bullet.x = hero.x;
		bullet.y = hero.y;
		bullet.setDirection(dx, dy);
		bullets.push(bullet);
		game.addChild(bullet);
		LK.getSound('shoot').play();
		// Rotate gun towards shot direction
		if (typeof hero.gunGfx !== "undefined") {
			hero.gunGfx.rotation = Math.atan2(dy, dx);
		}
	}
};
// Zombie spawn timer
var zombieSpawnInterval = 90; // frames
var zombieSpawnTimer = 0;
// Helper: spawn zombie at random edge
function spawnZombie() {
	var zombie = new Zombie();
	// Random edge: 0=top,1=bottom,2=left,3=right
	var edge = Math.floor(Math.random() * 4);
	var margin = 80;
	if (edge === 0) {
		// top
		zombie.x = margin + Math.random() * (GAME_W - 2 * margin);
		zombie.y = -zombie.radius;
	} else if (edge === 1) {
		// bottom
		zombie.x = margin + Math.random() * (GAME_W - 2 * margin);
		zombie.y = GAME_H + zombie.radius;
	} else if (edge === 2) {
		// left
		zombie.x = -zombie.radius;
		zombie.y = margin + Math.random() * (GAME_H - 2 * margin);
	} else {
		// right
		zombie.x = GAME_W + zombie.radius;
		zombie.y = margin + Math.random() * (GAME_H - 2 * margin);
	}
	zombie.setDirection(hero.x, hero.y);
	zombies.push(zombie);
	game.addChild(zombie);
}
// Main update loop
game.update = function () {
	// Update zombies
	for (var i = zombies.length - 1; i >= 0; i--) {
		var z = zombies[i];
		// Always update direction towards hero
		z.setDirection(hero.x, hero.y);
		z.update();
		// Check collision with hero
		var dx = z.x - hero.x;
		var dy = z.y - hero.y;
		var dist = Math.sqrt(dx * dx + dy * dy);
		if (dist < z.radius + hero.radius - 10) {
			// Game over
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
			return;
		}
	}
	// Update bullets
	for (var j = bullets.length - 1; j >= 0; j--) {
		var b = bullets[j];
		b.update();
		// Remove if out of bounds
		if (b.x < -b.radius || b.x > GAME_W + b.radius || b.y < -b.radius || b.y > GAME_H + b.radius) {
			b.destroy();
			bullets.splice(j, 1);
			continue;
		}
		// Check collision with zombies
		for (var k = zombies.length - 1; k >= 0; k--) {
			var z2 = zombies[k];
			var dx2 = b.x - z2.x;
			var dy2 = b.y - z2.y;
			var dist2 = Math.sqrt(dx2 * dx2 + dy2 * dy2);
			if (dist2 < b.radius + z2.radius - 10) {
				// Zombie killed
				z2.destroy();
				zombies.splice(k, 1);
				b.destroy();
				bullets.splice(j, 1);
				// Score up
				score += 1;
				scoreTxt.setText(score);
				break;
			}
		}
	}
	// Spawn zombies
	zombieSpawnTimer++;
	if (zombieSpawnTimer >= zombieSpawnInterval) {
		spawnZombie();
		zombieSpawnTimer = 0;
		// Gradually increase spawn rate
		if (zombieSpawnInterval > 30) zombieSpawnInterval -= 1;
	}
};
// Center hero on start
hero.x = GAME_W / 2;
hero.y = GAME_H / 2;
// Initial zombie spawn
for (var i = 0; i < 3; i++) {
	spawnZombie();
}

===================================================================
--- original.js
+++ change.js
@@ -38,10 +38,10 @@
 		anchorX: 0.5,
 		anchorY: 0.5
 	});
 	// Add a gun to hero's hand
-	// We'll use the bullet asset as a simple gun for now, positioned to the right hand
-	var gunGfx = self.attachAsset('bullet', {
+	// Use the new blue gun asset, positioned to the right hand
+	var gunGfx = self.attachAsset('bluegun', {
 		anchorX: 0.2,
 		anchorY: 0.5,
 		scaleX: 1.2,
 		scaleY: 0.6,
@@ -96,8 +96,9 @@
 
 /**** 
 * Game Code
 ****/ 
+// New blue gun asset
 // Game area
 // Hero asset: red box
 // Zombie asset: green ellipse
 // Bullet asset: yellow box