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

/**** 
* Classes
****/ 
// Aiming line class
var AimLine = Container.expand(function () {
	var self = Container.call(this);
	// Attach aim line asset, anchor at left (0,0.5)
	var lineGfx = self.attachAsset('aimLine', {
		anchorX: 0,
		anchorY: 0.5
	});
	// Set default scale
	lineGfx.scaleY = 0.2; // Thin line
	// Set color, etc. if needed
	return self;
});
// Bullet class
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	// Attach bullet asset, center anchor
	var bulletGfx = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Direction vector (set on spawn)
	self.dx = 0;
	self.dy = 0;
	self.speed = 40; // px per frame
	self.update = function () {
		self.x += self.dx * self.speed;
		self.y += self.dy * self.speed;
	};
	return self;
});
// Gun/player class
var Gun = Container.expand(function () {
	var self = Container.call(this);
	// Attach gun asset, center anchor
	var gunGfx = self.attachAsset('gun', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// For possible future use: gunGfx
	return self;
});
// Zombie class
var Zombie = Container.expand(function () {
	var self = Container.call(this);
	// Attach zombie asset, center anchor
	var zombieGfx = self.attachAsset('zombie', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Target position (player center)
	self.targetX = 0;
	self.targetY = 0;
	self.speed = 4 + Math.random() * 2; // Slight speed variation
	self.update = function () {
		// Move toward target
		var dx = self.targetX - self.x;
		var dy = self.targetY - self.y;
		var dist = Math.sqrt(dx * dx + dy * dy);
		if (dist > 0) {
			self.x += dx / dist * self.speed;
			self.y += dy / dist * self.speed;
		}
	};
	return self;
});

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

/**** 
* Game Code
****/ 
// Aiming line: thin yellow box (will be scaled)
// Zombie asset: greenish box
// Bullet asset: small ellipse
// Gun (player) asset: a box, centered
// Game constants
var GAME_W = 2048;
var GAME_H = 2732;
var PLAYER_X = GAME_W / 2;
var PLAYER_Y = GAME_H / 2; // Center of the screen
// Game state
var bullets = [];
var zombies = [];
var score = 0;
var isGameOver = false;
// Create gun/player
var gun = new Gun();
gun.x = PLAYER_X;
gun.y = PLAYER_Y;
game.addChild(gun);
// Create aiming line
var aimLine = new AimLine();
aimLine.x = gun.x;
aimLine.y = gun.y;
game.addChild(aimLine);
// Score text
var scoreTxt = new Text2('0', {
	size: 120,
	fill: "#fff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Helper: clamp
function clamp(val, min, max) {
	return Math.max(min, Math.min(max, val));
}
// Helper: spawn zombie at random edge, aiming at player
function spawnZombie() {
	var z = new Zombie();
	// Pick random edge: 0=top, 1=bottom, 2=left, 3=right
	var edge = Math.floor(Math.random() * 4);
	var x, y;
	if (edge === 0) {
		// top
		x = 200 + Math.random() * (GAME_W - 400);
		y = -80;
	} else if (edge === 1) {
		// bottom
		x = 200 + Math.random() * (GAME_W - 400);
		y = GAME_H + 80;
	} else if (edge === 2) {
		// left
		x = -80;
		y = 300 + Math.random() * (GAME_H - 600);
	} else {
		// right
		x = GAME_W + 80;
		y = 300 + Math.random() * (GAME_H - 600);
	}
	z.x = x;
	z.y = y;
	z.targetX = gun.x;
	z.targetY = gun.y;
	zombies.push(z);
	game.addChild(z);
}
// Helper: fire bullet toward (tx,ty)
function fireBullet(tx, ty) {
	// Direction vector from gun to (tx,ty)
	var dx = tx - gun.x;
	var dy = ty - gun.y;
	var dist = Math.sqrt(dx * dx + dy * dy);
	if (dist < 10) return; // Don't fire if too close
	dx /= dist;
	dy /= dist;
	var b = new Bullet();
	b.x = gun.x + dx * 80; // Start a bit ahead of gun
	b.y = gun.y + dy * 80;
	b.dx = dx;
	b.dy = dy;
	bullets.push(b);
	game.addChild(b);
}
// Update aiming line to point from gun to (aimX, aimY)
function updateAimLine(aimX, aimY) {
	var dx = aimX - gun.x;
	var dy = aimY - gun.y;
	var dist = Math.sqrt(dx * dx + dy * dy);
	// Clamp min/max length
	var minLen = 120,
		maxLen = 700;
	var len = clamp(dist, minLen, maxLen);
	// Set scaleX of line
	aimLine.scale.x = len / 20; // asset width is 20
	// Set rotation
	aimLine.rotation = Math.atan2(dy, dx);
}
// Initial aim position: straight up
var aimX = gun.x;
var aimY = gun.y - 400;
updateAimLine(aimX, aimY);
// Touch/mouse move: update aim
game.move = function (x, y, obj) {
	// Clamp aim point to inside game area
	aimX = clamp(x, 100, GAME_W - 100);
	aimY = clamp(y, 100, GAME_H - 100);
	updateAimLine(aimX, aimY);
};
// Touch/mouse down: fire bullet
game.down = function (x, y, obj) {
	if (isGameOver) return;
	fireBullet(x, y);
};
// No drag, so up is not needed
// Game update loop
game.update = function () {
	if (isGameOver) return;
	// Update bullets
	for (var i = bullets.length - 1; i >= 0; i--) {
		var b = bullets[i];
		b.update();
		// Remove if out of bounds
		if (b.x < -100 || b.x > GAME_W + 100 || b.y < -100 || b.y > GAME_H + 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!
				z.destroy();
				zombies.splice(j, 1);
				b.destroy();
				bullets.splice(i, 1);
				// Score up
				score += 1;
				scoreTxt.setText(score);
				// Flash zombie green
				LK.effects.flashObject(gun, 0x00ff00, 200);
				break;
			}
		}
	}
	// Update zombies
	for (var k = zombies.length - 1; k >= 0; k--) {
		var z = zombies[k];
		z.update();
		// Check if zombie reached player (gun)
		if (z.intersects(gun)) {
			// Game over
			isGameOver = true;
			LK.effects.flashScreen(0xff0000, 1000);
			// Show game over and then leaderboard
			LK.showGameOver(function () {
				LK.showLeaderboard({
					score: score
				});
			});
			return;
		}
	}
	// Spawn zombies at intervals
	if (LK.ticks % 60 === 0) {
		// Every 1s
		// Increase spawn rate as score increases
		var toSpawn = 1 + Math.floor(score / 10);
		for (var s = 0; s < toSpawn; s++) {
			spawnZombie();
		}
	}
};
// Reset state on game restart
game.on('reset', function () {
	// Remove all bullets/zombies
	for (var i = 0; i < bullets.length; i++) bullets[i].destroy();
	for (var j = 0; j < zombies.length; j++) zombies[j].destroy();
	bullets = [];
	zombies = [];
	score = 0;
	isGameOver = false;
	scoreTxt.setText(score);
	// Reset aim
	aimX = gun.x;
	aimY = gun.y - 400;
	updateAimLine(aimX, aimY);
	// Add leaderboard button to GUI (top right)
	if (!game.leaderboardBtn) {
		var leaderboardBtn = new Text2("🏆", {
			size: 100,
			fill: 0xFFE066
		});
		leaderboardBtn.anchor.set(1, 0);
		leaderboardBtn.interactive = true;
		leaderboardBtn.buttonMode = true;
		leaderboardBtn.x = -40;
		leaderboardBtn.y = 20;
		leaderboardBtn.down = function () {
			LK.showLeaderboard({
				score: score
			});
		};
		LK.gui.topRight.addChild(leaderboardBtn);
		game.leaderboardBtn = leaderboardBtn;
	}
});

===================================================================
--- original.js
+++ change.js
@@ -90,9 +90,9 @@
 // Game constants
 var GAME_W = 2048;
 var GAME_H = 2732;
 var PLAYER_X = GAME_W / 2;
-var PLAYER_Y = GAME_H - 350; // Near bottom, but not at edge
+var PLAYER_Y = GAME_H / 2; // Center of the screen
 // Game state
 var bullets = [];
 var zombies = [];
 var score = 0;