/**** 
* 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.radius = bulletSprite.width / 2;
	self.speed = 32;
	self.dirX = 0;
	self.dirY = 0;
	self.lastIntersecting = false;
	self.lastY = self.y;
	return self;
});
// Hero class
var Hero = Container.expand(function () {
	var self = Container.call(this);
	var heroSprite = self.attachAsset('hero', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.radius = heroSprite.width / 2;
	// For powerup state
	self.powered = false;
	self.powerTimer = 0;
	// Flash effect for powerup
	self.flashTween = null;
	// Powerup visual effect
	self.setPowered = function (on) {
		if (on) {
			self.powered = true;
			// Flash hero yellow
			if (self.flashTween) tween.stop(heroSprite, {
				tint: true
			});
			heroSprite.tint = 0xffff00;
			self.flashTween = tween(heroSprite, {
				tint: 0xd83318
			}, {
				duration: 400,
				easing: tween.linear,
				onFinish: function onFinish() {
					heroSprite.tint = 0xffff00;
					self.flashTween = tween(heroSprite, {
						tint: 0xd83318
					}, {
						duration: 400,
						easing: tween.linear,
						onFinish: function onFinish() {
							heroSprite.tint = 0xffff00;
						}
					});
				}
			});
		} else {
			self.powered = false;
			if (self.flashTween) tween.stop(heroSprite, {
				tint: true
			});
			heroSprite.tint = 0xd83318;
		}
	};
	return self;
});
// MegaZombie class
var MegaZombie = Container.expand(function () {
	var self = Container.call(this);
	var megaZombieSprite = self.attachAsset('zombie', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Make it visually bigger
	megaZombieSprite.scaleX = 2;
	megaZombieSprite.scaleY = 2;
	self.radius = megaZombieSprite.width; // much bigger
	self.speed = 1.2; // slower than normal zombies
	self.targetX = 0;
	self.targetY = 0;
	self.alive = true;
	self.hp = 8; // takes 8 hits to kill
	self.lastIntersecting = false;
	self.lastY = self.y;
	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.radius = powerupSprite.width / 2;
	self.type = 'rapid'; // Only one type for now
	self.lastIntersecting = false;
	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
	});
	self.radius = zombieSprite.width / 2;
	self.speed = 2; // Will be set on spawn
	self.targetX = 0;
	self.targetY = 0;
	self.alive = true;
	self.lastIntersecting = false;
	self.lastY = self.y;
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x222222
});

/**** 
* Game Code
****/ 
// Game area
// Hero: red box
// Zombie: green ellipse
// Bullet: yellow box
// Base: blue box
// Powerup: purple ellipse
// Sound for shooting
// Music
var GAME_W = 2048;
var GAME_H = 2732;
// Base
var base = game.addChild(LK.getAsset('base', {
	anchorX: 0.5,
	anchorY: 0.5
}));
base.x = GAME_W / 2;
base.y = GAME_H - 120;
// Hero
var hero = new Hero();
game.addChild(hero);
hero.x = GAME_W / 2;
hero.y = GAME_H - 350;
// Arrow to reinforcements (base)
var arrowLength = 180;
var arrowWidth = 40;
var arrow = LK.getAsset('arrow', {
	anchorX: 0.0,
	anchorY: 0.5
});
arrow.alpha = 0.7;
game.addChild(arrow);
arrow.visible = true;
// Score
var score = 0;
var scoreTxt = new Text2('0', {
	size: 120,
	fill: "#fff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// High Score (not persistent, just for session)
var highScore = 0;
// Timer
var elapsedFrames = 0;
var timeTxt = new Text2('00:00', {
	size: 70,
	fill: "#fff"
});
timeTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(timeTxt);
timeTxt.y = 200;
// Wave
var wave = 1;
var waveTxt = new Text2('Wave 1', {
	size: 70,
	fill: "#fff"
});
waveTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(waveTxt);
waveTxt.y = 120;
// Arrays for game objects
var zombies = [];
var megaZombies = [];
var bullets = [];
var powerups = [];
// Gold
var gold = 0;
var goldTxt = new Text2('Gold: 0', {
	size: 70,
	fill: 0xFFE066
});
goldTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(goldTxt);
goldTxt.y = 320;
// Dragging
var dragNode = null;
// Shooting cooldown
var shootCooldown = 0;
var shootInterval = 18; // frames (0.3s at 60fps)
var rapidFire = false;
// Powerup timer
var powerupTimer = 0;
// Zombie spawn
var zombieSpawnTimer = 0;
var zombieSpawnInterval = 90; // frames (1.5s)
var zombiesPerWave = 6;
var zombiesSpawned = 0;
var zombiesToSpawn = zombiesPerWave;
// Powerup spawn
var powerupSpawnTimer = 0;
var powerupSpawnInterval = 600; // 10s
// Game state
var gameOver = false;
// Start music
LK.playMusic('bgmusic', {
	fade: {
		start: 0,
		end: 1,
		duration: 1000
	}
});
// Helper: clamp hero inside game area
function clampHero() {
	var margin = hero.radius + 20;
	if (hero.x < margin) hero.x = margin;
	if (hero.x > GAME_W - margin) hero.x = GAME_W - margin;
	if (hero.y < margin + 100) hero.y = margin + 100; // avoid top menu
	if (hero.y > base.y - hero.radius - 40) hero.y = base.y - hero.radius - 40;
}
// Helper: spawn a zombie at random edge, target base
function spawnZombie() {
	// Decide if this should be a mega zombie
	var isMega = false;
	// Start spawning mega zombies at wave 4, increase chance as wave rises
	if (wave >= 4) {
		// 10% at wave 4, 20% at wave 6, 30% at wave 8, max 40%
		var megaChance = Math.min(0.1 + 0.05 * (wave - 4), 0.4);
		if (Math.random() < megaChance) isMega = true;
	}
	// Random edge: 0=top, 1=left, 2=right
	var edge = Math.floor(Math.random() * 3);
	var zx, zy;
	if (edge === 0) {
		// top
		zx = 200 + Math.random() * (GAME_W - 400);
		zy = -80;
	} else if (edge === 1) {
		// left
		zx = -80;
		zy = 400 + Math.random() * (GAME_H - 1000);
	} else {
		// right
		zx = GAME_W + 80;
		zy = 400 + Math.random() * (GAME_H - 1000);
	}
	if (isMega) {
		var mz = new MegaZombie();
		mz.x = zx;
		mz.y = zy;
		mz.targetX = base.x;
		mz.targetY = base.y;
		// Slightly increase speed with wave, but always slower than normal zombies
		mz.speed = 1.2 + (wave - 4) * 0.1 + Math.random() * 0.2;
		megaZombies.push(mz);
		game.addChild(mz);
	} else {
		var z = new Zombie();
		z.x = zx;
		z.y = zy;
		z.targetX = base.x;
		z.targetY = base.y;
		z.speed = 2 + wave * 0.5 + Math.random();
		zombies.push(z);
		game.addChild(z);
	}
}
// Helper: spawn a powerup at random location
function spawnPowerup() {
	var p = new Powerup();
	p.x = 200 + Math.random() * (GAME_W - 400);
	p.y = 400 + Math.random() * (GAME_H - 1200);
	powerups.push(p);
	game.addChild(p);
}
// Helper: shoot bullet towards (tx, ty)
function shootBullet(tx, ty) {
	if (shootCooldown > 0) return;
	var b = new Bullet();
	b.x = hero.x;
	b.y = hero.y;
	// Direction
	var dx = tx - hero.x;
	var dy = ty - hero.y;
	var len = Math.sqrt(dx * dx + dy * dy);
	if (len === 0) {
		b.dirX = 0;
		b.dirY = -1;
	} else {
		b.dirX = dx / len;
		b.dirY = dy / len;
	}
	// If powered, increase speed
	b.speed = hero.powered ? 48 : 32;
	bullets.push(b);
	game.addChild(b);
	shootCooldown = hero.powered ? 6 : shootInterval;
	LK.getSound('shoot').play();
}
// Helper: start new wave
function startWave() {
	waveTxt.setText('Wave ' + wave);
	zombiesPerWave = 6 + (wave - 1) * 2;
	zombiesToSpawn = zombiesPerWave;
	zombiesSpawned = 0;
	zombieSpawnInterval = Math.max(40, 90 - wave * 5);
	// Clean up any remaining mega zombies (shouldn't be any, but for safety)
	for (var i = megaZombies.length - 1; i >= 0; i--) {
		if (megaZombies[i]) {
			megaZombies[i].destroy();
		}
	}
	megaZombies = [];
}
// Move handler: drag hero, shoot on tap
function handleMove(x, y, obj) {
	if (dragNode) {
		dragNode.x = x;
		dragNode.y = y;
		clampHero();
	}
}
// Down: start dragging hero or shoot if tap on zombie
game.down = function (x, y, obj) {
	// Check if tap on zombie
	for (var i = 0; i < zombies.length; i++) {
		var z = zombies[i];
		var dx = x - z.x;
		var dy = y - z.y;
		if (dx * dx + dy * dy < z.radius * z.radius) {
			// Shoot at zombie
			shootBullet(z.x, z.y);
			return;
		}
	}
	// Otherwise, drag hero
	var dxh = x - hero.x;
	var dyh = y - hero.y;
	if (dxh * dxh + dyh * dyh < hero.radius * hero.radius) {
		dragNode = hero;
	}
	// Also allow shooting by tapping anywhere else
	if (!dragNode) {
		shootBullet(x, y);
	}
	handleMove(x, y, obj);
};
game.move = handleMove;
game.up = function (x, y, obj) {
	dragNode = null;
};
// Main update loop
game.update = function () {
	if (gameOver) return;
	// Timer update
	elapsedFrames++;
	var seconds = Math.floor(elapsedFrames / 60);
	var min = Math.floor(seconds / 60);
	var sec = seconds % 60;
	var timeStr = (min < 10 ? "0" : "") + min + ":" + (sec < 10 ? "0" : "") + sec;
	timeTxt.setText(timeStr);
	// Every 20 seconds, increase zombies per wave and make them spawn faster
	if (elapsedFrames % (60 * 20) === 0 && elapsedFrames > 0) {
		zombiesPerWave += 2;
		zombieSpawnInterval = Math.max(20, zombieSpawnInterval - 5);
	}
	// Cooldowns
	if (shootCooldown > 0) shootCooldown--;
	// Powerup timer
	if (hero.powered) {
		hero.powerTimer--;
		if (hero.powerTimer <= 0) {
			hero.setPowered(false);
		}
	}
	// Powerup spawn
	powerupSpawnTimer++;
	if (powerupSpawnTimer >= powerupSpawnInterval) {
		powerupSpawnTimer = 0;
		spawnPowerup();
	}
	// Zombie spawn
	if (zombiesToSpawn > 0) {
		zombieSpawnTimer++;
		if (zombieSpawnTimer >= zombieSpawnInterval) {
			zombieSpawnTimer = 0;
			spawnZombie();
			zombiesToSpawn--;
			zombiesSpawned++;
		}
	} else if (zombies.length === 0) {
		// Next wave
		wave++;
		startWave();
		waveTxt.setText('Wave ' + wave + (wave >= 4 ? ' - Mega Zombies!' : ''));
	}
	// Update bullets
	for (var i = bullets.length - 1; i >= 0; i--) {
		var b = bullets[i];
		b.x += b.dirX * b.speed;
		b.y += b.dirY * b.speed;
		// Remove if off screen
		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
		var bulletDestroyed = false;
		for (var j = zombies.length - 1; j >= 0; j--) {
			var z = zombies[j];
			var dx = b.x - z.x;
			var dy = b.y - z.y;
			var dist2 = dx * dx + dy * dy;
			var r2 = (b.radius + z.radius) * (b.radius + z.radius);
			if (dist2 < r2) {
				// Hit!
				LK.getSound('zombiehit').play();
				score++;
				scoreTxt.setText(score);
				if (score > highScore) highScore = score;
				// Earn gold for killing zombie
				gold += 5;
				goldTxt.setText('Gold: ' + gold);
				// Remove zombie and bullet
				z.destroy();
				zombies.splice(j, 1);
				b.destroy();
				bullets.splice(i, 1);
				bulletDestroyed = true;
				break;
			}
		}
		if (bulletDestroyed) continue;
		// Check collision with mega zombies
		for (var j = megaZombies.length - 1; j >= 0; j--) {
			var mz = megaZombies[j];
			var dx = b.x - mz.x;
			var dy = b.y - mz.y;
			var dist2 = dx * dx + dy * dy;
			var r2 = (b.radius + mz.radius) * (b.radius + mz.radius);
			if (dist2 < r2) {
				// Hit mega zombie!
				LK.getSound('zombiehit').play();
				mz.hp--;
				// Flash mega zombie on hit
				LK.effects.flashObject(mz, 0xffff00, 200);
				if (mz.hp <= 0) {
					// Kill mega zombie
					score += 5; // Worth more points
					scoreTxt.setText(score);
					if (score > highScore) highScore = score;
					gold += 25; // More gold
					goldTxt.setText('Gold: ' + gold);
					mz.destroy();
					megaZombies.splice(j, 1);
				}
				// Destroy bullet
				b.destroy();
				bullets.splice(i, 1);
				break;
			}
		}
	}
	// Update zombies
	for (var i = zombies.length - 1; i >= 0; i--) {
		var z = zombies[i];
		// Move towards base
		var dx = base.x - z.x;
		var dy = base.y - z.y;
		var len = Math.sqrt(dx * dx + dy * dy);
		if (len > 0) {
			z.x += dx / len * z.speed;
			z.y += dy / len * z.speed;
		}
		// Check collision with base
		var dbx = z.x - base.x;
		var dby = z.y - base.y;
		var baseR = base.width / 2 + z.radius - 10;
		if (dbx * dbx + dby * dby < baseR * baseR) {
			// Game over
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
			gameOver = true;
			return;
		}
		// Check collision with hero (for fun, just flash)
		var dhx = z.x - hero.x;
		var dhy = z.y - hero.y;
		var heroR = hero.radius + z.radius;
		if (dhx * dhx + dhy * dhy < heroR * heroR) {
			LK.effects.flashObject(hero, 0xff0000, 300);
		}
	}
	// Update mega zombies
	for (var i = megaZombies.length - 1; i >= 0; i--) {
		var mz = megaZombies[i];
		// Move towards base
		var dx = base.x - mz.x;
		var dy = base.y - mz.y;
		var len = Math.sqrt(dx * dx + dy * dy);
		if (len > 0) {
			mz.x += dx / len * mz.speed;
			mz.y += dy / len * mz.speed;
		}
		// Check collision with base
		var dbx = mz.x - base.x;
		var dby = mz.y - base.y;
		var baseR = base.width / 2 + mz.radius - 10;
		if (dbx * dbx + dby * dby < baseR * baseR) {
			// Game over
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
			gameOver = true;
			return;
		}
		// Check collision with hero (for fun, just flash)
		var dhx = mz.x - hero.x;
		var dhy = mz.y - hero.y;
		var heroR = hero.radius + mz.radius;
		if (dhx * dhx + dhy * dhy < heroR * heroR) {
			LK.effects.flashObject(hero, 0xff0000, 300);
		}
	}
	// --- Arrow update and hero reaching base for reinforcements ---
	// Update arrow to point from hero to base
	if (arrow && hero && base) {
		var adx = base.x - hero.x;
		var ady = base.y - hero.y;
		var alen = Math.sqrt(adx * adx + ady * ady);
		if (alen > 0) {
			arrow.x = hero.x;
			arrow.y = hero.y;
			arrow.rotation = Math.atan2(ady, adx);
			arrow.visible = true;
			// Optionally, scale arrow based on distance (not required)
			// arrow.scaleX = Math.min(1, alen / 400);
		} else {
			arrow.visible = false;
		}
	}
	// Allow hero to reach base for reinforcements
	if (!gameOver) {
		var hbx = hero.x - base.x;
		var hby = hero.y - base.y;
		var heroBaseDist = Math.sqrt(hbx * hbx + hby * hby);
		var reinforceRadius = base.width / 2 + hero.radius + 10;
		if (hero.lastAtBase === undefined) hero.lastAtBase = false;
		var atBaseNow = heroBaseDist < reinforceRadius;
		if (!hero.lastAtBase && atBaseNow) {
			// Reached base for reinforcements!
			// Give bonus: restore powerup, gold, and flash hero
			hero.setPowered(true);
			hero.powerTimer = 180; // 3s rapid fire
			gold += 50;
			goldTxt.setText('Gold: ' + gold);
			LK.effects.flashObject(hero, 0x00ff00, 800);
			// Optionally, show a message (not required)
		}
		hero.lastAtBase = atBaseNow;
	}
	// Update powerups
	for (var i = powerups.length - 1; i >= 0; i--) {
		var p = powerups[i];
		var dx = p.x - hero.x;
		var dy = p.y - hero.y;
		var dist2 = dx * dx + dy * dy;
		var r2 = (p.radius + hero.radius) * (p.radius + hero.radius);
		if (dist2 < r2) {
			// Collect powerup
			LK.getSound('powerup').play();
			p.destroy();
			powerups.splice(i, 1);
			// Powerup: rapid fire for 5 seconds
			hero.setPowered(true);
			hero.powerTimer = 300; // 5s at 60fps
		}
	}
};
// Start first wave
startWave();

===================================================================
--- original.js
+++ change.js
@@ -151,8 +151,18 @@
 var hero = new Hero();
 game.addChild(hero);
 hero.x = GAME_W / 2;
 hero.y = GAME_H - 350;
+// Arrow to reinforcements (base)
+var arrowLength = 180;
+var arrowWidth = 40;
+var arrow = LK.getAsset('arrow', {
+	anchorX: 0.0,
+	anchorY: 0.5
+});
+arrow.alpha = 0.7;
+game.addChild(arrow);
+arrow.visible = true;
 // Score
 var score = 0;
 var scoreTxt = new Text2('0', {
 	size: 120,
@@ -532,8 +542,45 @@
 		if (dhx * dhx + dhy * dhy < heroR * heroR) {
 			LK.effects.flashObject(hero, 0xff0000, 300);
 		}
 	}
+	// --- Arrow update and hero reaching base for reinforcements ---
+	// Update arrow to point from hero to base
+	if (arrow && hero && base) {
+		var adx = base.x - hero.x;
+		var ady = base.y - hero.y;
+		var alen = Math.sqrt(adx * adx + ady * ady);
+		if (alen > 0) {
+			arrow.x = hero.x;
+			arrow.y = hero.y;
+			arrow.rotation = Math.atan2(ady, adx);
+			arrow.visible = true;
+			// Optionally, scale arrow based on distance (not required)
+			// arrow.scaleX = Math.min(1, alen / 400);
+		} else {
+			arrow.visible = false;
+		}
+	}
+	// Allow hero to reach base for reinforcements
+	if (!gameOver) {
+		var hbx = hero.x - base.x;
+		var hby = hero.y - base.y;
+		var heroBaseDist = Math.sqrt(hbx * hbx + hby * hby);
+		var reinforceRadius = base.width / 2 + hero.radius + 10;
+		if (hero.lastAtBase === undefined) hero.lastAtBase = false;
+		var atBaseNow = heroBaseDist < reinforceRadius;
+		if (!hero.lastAtBase && atBaseNow) {
+			// Reached base for reinforcements!
+			// Give bonus: restore powerup, gold, and flash hero
+			hero.setPowered(true);
+			hero.powerTimer = 180; // 3s rapid fire
+			gold += 50;
+			goldTxt.setText('Gold: ' + gold);
+			LK.effects.flashObject(hero, 0x00ff00, 800);
+			// Optionally, show a message (not required)
+		}
+		hero.lastAtBase = atBaseNow;
+	}
 	// Update powerups
 	for (var i = powerups.length - 1; i >= 0; i--) {
 		var p = powerups[i];
 		var dx = p.x - hero.x;