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

/**** 
* Classes
****/ 
var Boss = Container.expand(function () {
	var self = Container.call(this);
	// Boss main body (larger than regular enemy)
	var bossBody = self.attachAsset('enemyShipBody', {
		anchorX: 0.5,
		anchorY: 0.5,
		scaleX: 4,
		scaleY: 4
	});
	// Boss wings (scaled up)
	var bossWings = self.attachAsset('enemyShipWings', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 0,
		y: -60,
		scaleX: 5,
		scaleY: 3
	});
	// Boss core (scaled up)
	var bossCore = self.attachAsset('enemyShipCore', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 0,
		y: 0,
		scaleX: 3,
		scaleY: 3
	});
	// Boss thruster (scaled up)
	var bossThruster = self.attachAsset('enemyShipThruster', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 0,
		y: 120,
		scaleX: 4,
		scaleY: 4
	});
	self.health = 50;
	self.maxHealth = 50;
	self.speed = 1;
	self.shootTimer = 0;
	self.shootInterval = 30;
	self.moveTimer = 0;
	self.moveDirection = 1;
	self.lastHealth = self.health;
	self.update = function () {
		// Boss movement pattern - side to side
		self.moveTimer++;
		if (self.moveTimer % 120 == 0) {
			self.moveDirection *= -1;
		}
		self.x += self.moveDirection * 2;
		// Keep boss on screen
		if (self.x <= 200) {
			self.x = 200;
			self.moveDirection = 1;
		}
		if (self.x >= 1848) {
			self.x = 1848;
			self.moveDirection = -1;
		}
		// Boss shooting - multiple bullets
		self.shootTimer++;
		if (self.shootTimer >= self.shootInterval) {
			self.shootTimer = 0;
			// Fire 5 bullets in spread pattern
			for (var bulletIndex = 0; bulletIndex < 5; bulletIndex++) {
				var bullet = new EnemyBullet();
				bullet.x = self.x + (bulletIndex - 2) * 50;
				bullet.y = self.y + 80;
				bullet.lastY = bullet.y;
				bullet.speed = 6;
				enemyBullets.push(bullet);
				game.addChild(bullet);
			}
		}
	};
	return self;
});
var EnemyBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('enemyBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 8;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var EnemyShip = Container.expand(function () {
	var self = Container.call(this);
	// Main body
	var shipBody = self.attachAsset('enemyShipBody', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Wings
	var wings = self.attachAsset('enemyShipWings', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 0,
		y: -15
	});
	// Core/cockpit
	var core = self.attachAsset('enemyShipCore', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 0,
		y: 0
	});
	// Thruster
	var thruster = self.attachAsset('enemyShipThruster', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 0,
		y: 30
	});
	self.speed = 3;
	self.health = 1;
	self.shootTimer = 0;
	self.shootInterval = 60 + Math.random() * 120; // Random shooting interval
	self.update = function () {
		self.y += self.speed;
		// Enemy shooting logic
		self.shootTimer++;
		if (self.shootTimer >= self.shootInterval) {
			self.shootTimer = 0;
			self.shootInterval = 60 + Math.random() * 120; // Reset with new random interval
			// Create enemy bullet
			var bullet = new EnemyBullet();
			bullet.x = self.x;
			bullet.y = self.y + 40;
			bullet.lastY = bullet.y;
			enemyBullets.push(bullet);
			game.addChild(bullet);
		}
	};
	return self;
});
var PlayerBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('playerBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -12;
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});
var PlayerShip = Container.expand(function () {
	var self = Container.call(this);
	// Main body
	var shipBody = self.attachAsset('playerShipBody', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Wings
	var leftWing = self.attachAsset('playerShipWings', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 0,
		y: 20
	});
	// Cockpit
	var cockpit = self.attachAsset('playerShipCockpit', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 0,
		y: -15
	});
	// Engine thrusters
	var leftEngine = self.attachAsset('playerShipEngines', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: -25,
		y: 35
	});
	var rightEngine = self.attachAsset('playerShipEngines', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 25,
		y: 35
	});
	// Shield visual effect (initially hidden)
	var shieldGraphics = self.attachAsset('shieldEffect', {
		anchorX: 0.5,
		anchorY: 0.5,
		x: 0,
		y: 0,
		alpha: 0
	});
	self.shieldGraphics = shieldGraphics;
	self.shootTimer = 0;
	self.shootInterval = 15; // Shoot every 15 ticks (4 times per second)
	self.update = function () {
		// Auto-shooting logic
		self.shootTimer++;
		var currentShootInterval = playerUpgrades.rapidFire ? Math.floor(self.shootInterval / 2) : self.shootInterval;
		if (self.shootTimer >= currentShootInterval) {
			self.shootTimer = 0;
			if (playerUpgrades.tripleShot) {
				// Triple shot
				for (var shotIndex = 0; shotIndex < 3; shotIndex++) {
					var bullet = new PlayerBullet();
					bullet.x = self.x + (shotIndex - 1) * 30; // Spread shots
					bullet.y = self.y - 50;
					bullet.lastY = bullet.y;
					playerBullets.push(bullet);
					game.addChild(bullet);
				}
			} else {
				// Single shot
				var bullet = new PlayerBullet();
				bullet.x = self.x;
				bullet.y = self.y - 50;
				bullet.lastY = bullet.y;
				playerBullets.push(bullet);
				game.addChild(bullet);
			}
			LK.getSound('shoot').play();
		}
	};
	return self;
});
var Upgrade = Container.expand(function (type) {
	var self = Container.call(this);
	self.type = type;
	self.speed = 4;
	var upgradeGraphics = self.attachAsset('upgrade' + type, {
		anchorX: 0.5,
		anchorY: 0.5
	});
	// Pulsing animation
	tween(upgradeGraphics, {
		scaleX: 1.2,
		scaleY: 1.2
	}, {
		duration: 800,
		easing: tween.easeInOut,
		onFinish: function onFinish() {
			tween(upgradeGraphics, {
				scaleX: 1.0,
				scaleY: 1.0
			}, {
				duration: 800,
				easing: tween.easeInOut,
				onFinish: function onFinish() {
					// Restart the pulsing animation
					if (self.parent) {
						tween(upgradeGraphics, {
							scaleX: 1.2,
							scaleY: 1.2
						}, {
							duration: 800,
							easing: tween.easeInOut,
							onFinish: arguments.callee.caller
						});
					}
				}
			});
		}
	});
	self.update = function () {
		self.y += self.speed;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x000011
});

/**** 
* Game Code
****/ 
// Game variables
var playerBullets = [];
var enemyBullets = [];
var enemies = [];
var bosses = [];
var upgrades = [];
var enemySpawnTimer = 0;
var enemySpawnInterval = 120; // Start with 2 seconds between spawns
var upgradeSpawnTimer = 0;
var upgradeSpawnInterval = 600; // 10 seconds between upgrades
var dragNode = null;
var difficultyTimer = 0;
// Upgrade system
var playerUpgrades = {
	rapidFire: false,
	rapidFireTimer: 0,
	shield: false,
	shieldTimer: 0,
	tripleShot: false,
	tripleShotTimer: 0
};
// Permanent upgrade system
var permanentUpgrades = storage.permanentUpgrades || {
	damageLevel: 1,
	speedLevel: 1,
	healthLevel: 1
};
var upgradeCosts = {
	damageLevel: 100,
	speedLevel: 150,
	healthLevel: 200
};
// Current player stats based on permanent upgrades
var playerStats = {
	damage: permanentUpgrades.damageLevel,
	speed: 1 + (permanentUpgrades.speedLevel - 1) * 0.3,
	health: permanentUpgrades.healthLevel
};
var playerHealth = playerStats.health;
var maxPlayerHealth = playerStats.health;
// Create player ship
var player = game.addChild(new PlayerShip());
player.x = 1024; // Center horizontally
player.y = 2400; // Near bottom of screen
// Create game title
var titleTxt = new Text2('SPACE INVADERS 2.0', {
	size: 80,
	fill: 0x00ff00
});
titleTxt.anchor.set(0.5, 0);
titleTxt.x = 0;
titleTxt.y = 20;
LK.gui.top.addChild(titleTxt);
// Create score display
var scoreTxt = new Text2('0', {
	size: 120,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
scoreTxt.y = 120;
LK.gui.top.addChild(scoreTxt);
scoreTxt.setText(LK.getScore());
// Create boss health bar (initially hidden)
var bossHealthBarBg = LK.getAsset('bossHealthBarBg', {
	anchorX: 0.5,
	anchorY: 0,
	alpha: 0
});
var bossHealthBarFill = LK.getAsset('bossHealthBarFill', {
	anchorX: 0,
	anchorY: 0,
	alpha: 0
});
bossHealthBarBg.x = 0;
bossHealthBarBg.y = 220;
bossHealthBarFill.x = -200;
bossHealthBarFill.y = 0;
LK.gui.top.addChild(bossHealthBarBg);
bossHealthBarBg.addChild(bossHealthBarFill);
// Boss health bar text
var bossHealthTxt = new Text2('BOSS', {
	size: 40,
	fill: 0xff0000
});
bossHealthTxt.anchor.set(0.5, 0);
bossHealthTxt.x = 0;
bossHealthTxt.y = 250;
bossHealthTxt.alpha = 0;
LK.gui.top.addChild(bossHealthTxt);
// Upgrade Shop UI
var shopButton = new Text2('UPGRADES', {
	size: 60,
	fill: 0x00ff00
});
shopButton.anchor.set(1, 0);
shopButton.x = -20;
shopButton.y = 20;
LK.gui.topRight.addChild(shopButton);
var shopVisible = false;
var shopContainer = new Container();
shopContainer.alpha = 0;
LK.gui.center.addChild(shopContainer);
// Shop background
var shopBg = LK.getAsset('enemyShipBody', {
	anchorX: 0.5,
	anchorY: 0.5,
	scaleX: 12,
	scaleY: 8,
	alpha: 0.8
});
shopContainer.addChild(shopBg);
// Shop title
var shopTitle = new Text2('PERMANENT UPGRADES', {
	size: 70,
	fill: 0x00ff00
});
shopTitle.anchor.set(0.5, 0.5);
shopTitle.y = -250;
shopContainer.addChild(shopTitle);
// Damage upgrade
var damageUpgradeText = new Text2('DAMAGE LV.' + permanentUpgrades.damageLevel + ' - COST: ' + upgradeCosts.damageLevel * permanentUpgrades.damageLevel, {
	size: 50,
	fill: 0xffffff
});
damageUpgradeText.anchor.set(0.5, 0.5);
damageUpgradeText.y = -100;
shopContainer.addChild(damageUpgradeText);
// Speed upgrade
var speedUpgradeText = new Text2('SPEED LV.' + permanentUpgrades.speedLevel + ' - COST: ' + upgradeCosts.speedLevel * permanentUpgrades.speedLevel, {
	size: 50,
	fill: 0xffffff
});
speedUpgradeText.anchor.set(0.5, 0.5);
speedUpgradeText.y = 0;
shopContainer.addChild(speedUpgradeText);
// Health upgrade
var healthUpgradeText = new Text2('HEALTH LV.' + permanentUpgrades.healthLevel + ' - COST: ' + upgradeCosts.healthLevel * permanentUpgrades.healthLevel, {
	size: 50,
	fill: 0xffffff
});
healthUpgradeText.anchor.set(0.5, 0.5);
healthUpgradeText.y = 100;
shopContainer.addChild(healthUpgradeText);
// Close button
var closeButton = new Text2('CLOSE', {
	size: 60,
	fill: 0xff0000
});
closeButton.anchor.set(0.5, 0.5);
closeButton.y = 200;
shopContainer.addChild(closeButton);
// Upgrade button in left corner
var upgradeButton = new Text2('UPGRADE', {
	size: 50,
	fill: 0x00ff00
});
upgradeButton.anchor.set(0, 0);
upgradeButton.x = 120; // Position to avoid the menu icon area
upgradeButton.y = 20;
LK.gui.topLeft.addChild(upgradeButton);
// Player health display
var healthTxt = new Text2('HEALTH: ' + playerHealth + '/' + maxPlayerHealth, {
	size: 60,
	fill: 0xff4444
});
healthTxt.anchor.set(0, 0);
healthTxt.x = 20;
healthTxt.y = 300;
LK.gui.topLeft.addChild(healthTxt);
// Stick control variables
var stickActive = false;
var stickStartX = 0;
var stickStartY = 0;
var stickCurrentX = 0;
var stickCurrentY = 0;
var maxStickDistance = 150;
// Touch controls for stick movement
function handleMove(x, y, obj) {
	if (stickActive) {
		stickCurrentX = x;
		stickCurrentY = y;
		// Calculate distance from start point
		var deltaX = stickCurrentX - stickStartX;
		var deltaY = stickCurrentY - stickStartY;
		var distance = Math.sqrt(deltaX * deltaX + deltaY * deltaY);
		// Limit stick movement to max distance
		if (distance > maxStickDistance) {
			var angle = Math.atan2(deltaY, deltaX);
			deltaX = Math.cos(angle) * maxStickDistance;
			deltaY = Math.sin(angle) * maxStickDistance;
			stickCurrentX = stickStartX + deltaX;
			stickCurrentY = stickStartY + deltaY;
		}
	}
}
game.move = handleMove;
game.down = function (x, y, obj) {
	// Check shop interactions
	if (shopVisible) {
		var localPos = shopContainer.toLocal({
			x: x,
			y: y
		});
		// Check upgrade purchases
		if (Math.abs(localPos.x) < 400 && Math.abs(localPos.y + 100) < 25) {
			// Damage upgrade clicked
			var cost = upgradeCosts.damageLevel * permanentUpgrades.damageLevel;
			if (LK.getScore() >= cost) {
				LK.setScore(LK.getScore() - cost);
				permanentUpgrades.damageLevel++;
				playerStats.damage = permanentUpgrades.damageLevel;
				storage.permanentUpgrades = permanentUpgrades;
				damageUpgradeText.setText('DAMAGE LV.' + permanentUpgrades.damageLevel + ' - COST: ' + upgradeCosts.damageLevel * permanentUpgrades.damageLevel);
				scoreTxt.setText(LK.getScore());
				LK.effects.flashScreen(0x00ff00, 300);
			}
			return;
		}
		if (Math.abs(localPos.x) < 400 && Math.abs(localPos.y) < 25) {
			// Speed upgrade clicked
			var cost = upgradeCosts.speedLevel * permanentUpgrades.speedLevel;
			if (LK.getScore() >= cost) {
				LK.setScore(LK.getScore() - cost);
				permanentUpgrades.speedLevel++;
				playerStats.speed = 1 + (permanentUpgrades.speedLevel - 1) * 0.3;
				storage.permanentUpgrades = permanentUpgrades;
				speedUpgradeText.setText('SPEED LV.' + permanentUpgrades.speedLevel + ' - COST: ' + upgradeCosts.speedLevel * permanentUpgrades.speedLevel);
				scoreTxt.setText(LK.getScore());
				LK.effects.flashScreen(0x00ff00, 300);
			}
			return;
		}
		if (Math.abs(localPos.x) < 400 && Math.abs(localPos.y - 100) < 25) {
			// Health upgrade clicked
			var cost = upgradeCosts.healthLevel * permanentUpgrades.healthLevel;
			if (LK.getScore() >= cost) {
				LK.setScore(LK.getScore() - cost);
				permanentUpgrades.healthLevel++;
				playerStats.health = permanentUpgrades.healthLevel;
				maxPlayerHealth = playerStats.health;
				playerHealth = maxPlayerHealth; // Heal to full
				storage.permanentUpgrades = permanentUpgrades;
				healthUpgradeText.setText('HEALTH LV.' + permanentUpgrades.healthLevel + ' - COST: ' + upgradeCosts.healthLevel * permanentUpgrades.healthLevel);
				healthTxt.setText('HEALTH: ' + playerHealth + '/' + maxPlayerHealth);
				scoreTxt.setText(LK.getScore());
				LK.effects.flashScreen(0x00ff00, 300);
			}
			return;
		}
		if (Math.abs(localPos.x) < 200 && Math.abs(localPos.y - 200) < 30) {
			// Close button clicked
			shopVisible = false;
			tween(shopContainer, {
				alpha: 0
			}, {
				duration: 300,
				easing: tween.easeOut
			});
			return;
		}
	} else {
		// Check if upgrade button clicked (left corner)
		var upgradeButtonPos = LK.gui.topLeft.toLocal({
			x: x,
			y: y
		});
		if (upgradeButtonPos.x >= 120 && upgradeButtonPos.x <= 280 && upgradeButtonPos.y >= 20 && upgradeButtonPos.y <= 70) {
			shopVisible = true;
			tween(shopContainer, {
				alpha: 1
			}, {
				duration: 300,
				easing: tween.easeIn
			});
			return;
		}
		// Check if shop button clicked
		var shopButtonPos = LK.gui.topRight.toLocal({
			x: x,
			y: y
		});
		if (shopButtonPos.x >= -220 && shopButtonPos.x <= -20 && shopButtonPos.y >= 20 && shopButtonPos.y <= 80) {
			shopVisible = true;
			tween(shopContainer, {
				alpha: 1
			}, {
				duration: 300,
				easing: tween.easeIn
			});
			return;
		}
	}
	if (!shopVisible) {
		stickActive = true;
		stickStartX = x;
		stickStartY = y;
		stickCurrentX = x;
		stickCurrentY = y;
	}
};
game.up = function (x, y, obj) {
	stickActive = false;
};
game.update = function () {
	// Move player based on stick input
	if (stickActive && !shopVisible) {
		var deltaX = stickCurrentX - stickStartX;
		var deltaY = stickCurrentY - stickStartY;
		// Normalize movement based on stick distance
		var moveSpeed = 16 * playerStats.speed;
		var normalizedX = deltaX / maxStickDistance;
		var normalizedY = deltaY / maxStickDistance;
		// Apply movement
		player.x += normalizedX * moveSpeed;
		player.y += normalizedY * moveSpeed;
		// Keep player within screen bounds
		player.x = Math.max(40, Math.min(2008, player.x));
		player.y = Math.max(100, Math.min(2632, player.y));
	}
	// Update difficulty over time
	difficultyTimer++;
	if (difficultyTimer % 600 == 0) {
		// Every 10 seconds
		enemySpawnInterval = Math.max(30, enemySpawnInterval - 10); // Faster spawning, minimum 0.5 seconds
	}
	// Update upgrade timers
	if (playerUpgrades.rapidFire) {
		playerUpgrades.rapidFireTimer--;
		if (playerUpgrades.rapidFireTimer <= 0) {
			playerUpgrades.rapidFire = false;
			// Flash effect when upgrade expires
			LK.effects.flashObject(player, 0x00ff00, 300);
		}
	}
	if (playerUpgrades.shield) {
		playerUpgrades.shieldTimer--;
		if (playerUpgrades.shieldTimer <= 0) {
			playerUpgrades.shield = false;
			player.alpha = 1.0; // Reset transparency
			// Hide shield visual effect
			tween.stop(player.shieldGraphics);
			tween(player.shieldGraphics, {
				alpha: 0
			}, {
				duration: 300,
				easing: tween.easeOut
			});
		}
	}
	if (playerUpgrades.tripleShot) {
		playerUpgrades.tripleShotTimer--;
		if (playerUpgrades.tripleShotTimer <= 0) {
			playerUpgrades.tripleShot = false;
			// Flash effect when upgrade expires
			LK.effects.flashObject(player, 0xff0080, 300);
		}
	}
	// Spawn upgrades
	upgradeSpawnTimer++;
	if (upgradeSpawnTimer >= upgradeSpawnInterval) {
		upgradeSpawnTimer = 0;
		var upgradeTypes = ['RapidFire', 'Shield', 'TripleShot'];
		var randomType = upgradeTypes[Math.floor(Math.random() * upgradeTypes.length)];
		var upgrade = new Upgrade(randomType);
		upgrade.x = 100 + Math.random() * 1848;
		upgrade.y = -50;
		upgrade.lastY = upgrade.y;
		upgrades.push(upgrade);
		game.addChild(upgrade);
	}
	// Spawn enemies (but not during boss battles)
	enemySpawnTimer++;
	if (enemySpawnTimer >= enemySpawnInterval && bosses.length === 0) {
		enemySpawnTimer = 0;
		var enemy = new EnemyShip();
		enemy.x = 100 + Math.random() * 1848; // Random x position within screen
		enemy.y = -50; // Start above screen
		enemy.lastY = enemy.y;
		enemy.speed = 2 + Math.random() * 3 + LK.getScore() / 50; // Increase speed with score
		enemies.push(enemy);
		game.addChild(enemy);
	}
	// Update and check player bullets
	for (var i = playerBullets.length - 1; i >= 0; i--) {
		var bullet = playerBullets[i];
		if (bullet.lastY === undefined) {
			bullet.lastY = bullet.y;
		}
		// Remove bullets that go off screen
		if (bullet.lastY >= -25 && bullet.y < -25) {
			bullet.destroy();
			playerBullets.splice(i, 1);
			continue;
		}
		// Check collision with enemies
		var hitEnemy = false;
		for (var j = enemies.length - 1; j >= 0; j--) {
			var enemy = enemies[j];
			if (bullet.intersects(enemy)) {
				// Deal damage based on upgrade level
				enemy.health -= playerStats.damage;
				bullet.destroy();
				playerBullets.splice(i, 1);
				hitEnemy = true;
				if (enemy.health <= 0) {
					// Enemy destroyed
					LK.setScore(LK.getScore() + 10);
					scoreTxt.setText(LK.getScore());
					// Visual effect
					LK.effects.flashObject(enemy, 0xffffff, 200);
					// Clean up
					enemy.destroy();
					enemies.splice(j, 1);
					LK.getSound('enemyDestroy').play();
				} else {
					// Enemy damaged but not destroyed
					LK.effects.flashObject(enemy, 0xff0000, 100);
				}
				break;
			}
		}
		if (!hitEnemy) {
			bullet.lastY = bullet.y;
		}
	}
	// Update and check enemy bullets
	for (var i = enemyBullets.length - 1; i >= 0; i--) {
		var bullet = enemyBullets[i];
		if (bullet.lastY === undefined) {
			bullet.lastY = bullet.y;
		}
		// Remove bullets that go off screen
		if (bullet.lastY <= 2757 && bullet.y > 2757) {
			bullet.destroy();
			enemyBullets.splice(i, 1);
			continue;
		}
		// Check collision with player
		if (bullet.intersects(player)) {
			if (!playerUpgrades.shield) {
				playerHealth--;
				healthTxt.setText('HEALTH: ' + playerHealth + '/' + maxPlayerHealth);
				LK.effects.flashObject(player, 0xff0000, 300);
				LK.getSound('playerHit').play();
				if (playerHealth <= 0) {
					LK.showGameOver();
					return;
				}
			} else {
				// Shield absorbs the hit
				LK.effects.flashObject(player, 0x0080ff, 200);
			}
			bullet.destroy();
			enemyBullets.splice(i, 1);
			continue;
		}
		bullet.lastY = bullet.y;
	}
	// Update and check upgrades
	for (var i = upgrades.length - 1; i >= 0; i--) {
		var upgrade = upgrades[i];
		if (upgrade.lastY === undefined) {
			upgrade.lastY = upgrade.y;
		}
		// Remove upgrades that go off screen
		if (upgrade.lastY <= 2757 && upgrade.y > 2757) {
			upgrade.destroy();
			upgrades.splice(i, 1);
			continue;
		}
		// Check collision with player
		if (upgrade.intersects(player)) {
			LK.getSound('upgradePickup').play();
			if (upgrade.type === 'RapidFire') {
				playerUpgrades.rapidFire = true;
				playerUpgrades.rapidFireTimer = 600; // 10 seconds
				LK.effects.flashObject(player, 0x00ff00, 500);
			} else if (upgrade.type === 'Shield') {
				playerUpgrades.shield = true;
				playerUpgrades.shieldTimer = 600; // 10 seconds
				player.alpha = 0.7; // Make player semi-transparent to show shield
				// Show shield visual effect
				player.shieldGraphics.alpha = 0.6;
				// Start pulsing animation for shield
				tween(player.shieldGraphics, {
					alpha: 0.3
				}, {
					duration: 500,
					easing: tween.easeInOut,
					onFinish: function onFinish() {
						if (playerUpgrades.shield) {
							tween(player.shieldGraphics, {
								alpha: 0.6
							}, {
								duration: 500,
								easing: tween.easeInOut,
								onFinish: arguments.callee.caller
							});
						}
					}
				});
				LK.effects.flashObject(player, 0x0080ff, 500);
			} else if (upgrade.type === 'TripleShot') {
				playerUpgrades.tripleShot = true;
				playerUpgrades.tripleShotTimer = 600; // 10 seconds
				LK.effects.flashObject(player, 0xff0080, 500);
			}
			upgrade.destroy();
			upgrades.splice(i, 1);
			continue;
		}
		upgrade.lastY = upgrade.y;
	}
	// Boss spawn logic - spawn immediately at 500 points and stay until killed
	var currentScore = LK.getScore();
	var shouldSpawnBoss = false;
	if (currentScore >= 500 && bosses.length === 0) {
		shouldSpawnBoss = true;
	}
	if (shouldSpawnBoss) {
		var boss = new Boss();
		boss.x = 1024;
		boss.y = 200;
		boss.lastY = boss.y;
		boss.lastHealth = boss.health;
		bosses.push(boss);
		game.addChild(boss);
		LK.effects.flashScreen(0xff0000, 500);
		// Show boss health bar
		bossHealthBarBg.alpha = 1;
		bossHealthBarFill.alpha = 1;
		bossHealthTxt.alpha = 1;
	}
	// Update and check bosses
	for (var i = bosses.length - 1; i >= 0; i--) {
		var boss = bosses[i];
		if (boss.lastY === undefined) {
			boss.lastY = boss.y;
		}
		if (boss.lastHealth === undefined) {
			boss.lastHealth = boss.health;
		}
		// Check collision with player bullets
		for (var j = playerBullets.length - 1; j >= 0; j--) {
			var bullet = playerBullets[j];
			if (bullet.intersects(boss)) {
				boss.health -= playerStats.damage;
				LK.effects.flashObject(boss, 0xffffff, 100);
				bullet.destroy();
				playerBullets.splice(j, 1);
				// Update boss health bar
				var healthPercentage = boss.health / boss.maxHealth;
				bossHealthBarFill.scaleX = healthPercentage;
				if (boss.health <= 0) {
					// Boss defeated
					LK.setScore(LK.getScore() + 500);
					scoreTxt.setText(LK.getScore());
					LK.effects.flashObject(boss, 0xffffff, 1000);
					boss.destroy();
					bosses.splice(i, 1);
					LK.getSound('enemyDestroy').play();
					// Hide boss health bar
					bossHealthBarBg.alpha = 0;
					bossHealthBarFill.alpha = 0;
					bossHealthTxt.alpha = 0;
					break;
				}
			}
		}
		// Check collision with player
		if (boss.intersects(player)) {
			if (!playerUpgrades.shield) {
				playerHealth -= 2; // Boss does more damage
				healthTxt.setText('HEALTH: ' + playerHealth + '/' + maxPlayerHealth);
				LK.effects.flashObject(player, 0xff0000, 500);
				LK.getSound('playerHit').play();
				if (playerHealth <= 0) {
					LK.showGameOver();
					return;
				}
			} else {
				LK.setScore(LK.getScore() + 10);
				scoreTxt.setText(LK.getScore());
				LK.effects.flashObject(player, 0x0080ff, 200);
			}
		}
		boss.lastY = boss.y;
		boss.lastHealth = boss.health;
	}
	// Update and check enemies
	for (var i = enemies.length - 1; i >= 0; i--) {
		var enemy = enemies[i];
		if (enemy.lastY === undefined) {
			enemy.lastY = enemy.y;
		}
		// Remove enemies that go off screen
		if (enemy.lastY <= 2757 && enemy.y > 2757) {
			enemy.destroy();
			enemies.splice(i, 1);
			continue;
		}
		// Check collision with player
		if (enemy.intersects(player)) {
			if (!playerUpgrades.shield) {
				playerHealth--;
				healthTxt.setText('HEALTH: ' + playerHealth + '/' + maxPlayerHealth);
				LK.effects.flashObject(player, 0xff0000, 300);
				LK.getSound('playerHit').play();
				if (playerHealth <= 0) {
					LK.showGameOver();
					return;
				}
			} else {
				// Shield absorbs the hit and destroys the enemy
				LK.setScore(LK.getScore() + 5); // Bonus points for shield collision
				scoreTxt.setText(LK.getScore());
				LK.effects.flashObject(player, 0x0080ff, 200);
			}
			enemy.destroy();
			enemies.splice(i, 1);
			continue;
		}
		enemy.lastY = enemy.y;
	}
};

===================================================================
--- original.js
+++ change.js
@@ -438,8 +438,17 @@
 });
 closeButton.anchor.set(0.5, 0.5);
 closeButton.y = 200;
 shopContainer.addChild(closeButton);
+// Upgrade button in left corner
+var upgradeButton = new Text2('UPGRADE', {
+	size: 50,
+	fill: 0x00ff00
+});
+upgradeButton.anchor.set(0, 0);
+upgradeButton.x = 120; // Position to avoid the menu icon area
+upgradeButton.y = 20;
+LK.gui.topLeft.addChild(upgradeButton);
 // Player health display
 var healthTxt = new Text2('HEALTH: ' + playerHealth + '/' + maxPlayerHealth, {
 	size: 60,
 	fill: 0xff4444
@@ -539,8 +548,23 @@
 			});
 			return;
 		}
 	} else {
+		// Check if upgrade button clicked (left corner)
+		var upgradeButtonPos = LK.gui.topLeft.toLocal({
+			x: x,
+			y: y
+		});
+		if (upgradeButtonPos.x >= 120 && upgradeButtonPos.x <= 280 && upgradeButtonPos.y >= 20 && upgradeButtonPos.y <= 70) {
+			shopVisible = true;
+			tween(shopContainer, {
+				alpha: 1
+			}, {
+				duration: 300,
+				easing: tween.easeIn
+			});
+			return;
+		}
 		// Check if shop button clicked
 		var shopButtonPos = LK.gui.topRight.toLocal({
 			x: x,
 			y: y