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

/**** 
* Classes
****/ 
// Enemy
var Enemy = Container.expand(function () {
	var self = Container.call(this);
	var gfx = self.attachAsset('enemy', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = gfx.width;
	self.height = gfx.height;
	self.speedY = 6;
	self.hp = 1;
	self.maxHp = 1;
	self.shootCooldown = 0;
	self.shootRate = 90 + Math.floor(Math.random() * 60);
	self.value = 1;
	self.update = function () {
		// Move enemy down until it reaches about the middle of the screen, then stop
		if (self.lastY === undefined) self.lastY = self.y;
		var stopY = 1366; // Middle of 2732px screen
		if (self.y < stopY) {
			self.y += self.speedY;
			if (self.y > stopY) self.y = stopY;
		}
		if (self.shootCooldown > 0) self.shootCooldown--;
		if (self.shootCooldown === 0 && Math.random() < 0.02) {
			self.shoot();
			self.shootCooldown = self.shootRate;
		}
		self.lastY = self.y;
	};
	self.shoot = function () {
		var bullet = new EnemyBullet();
		bullet.x = self.x;
		bullet.y = self.y + self.height / 2 + 10;
		enemyBullets.push(bullet);
		game.addChild(bullet);
		LK.getSound('enemyShoot').play();
	};
	self.takeDamage = function (amount) {
		self.hp -= amount;
		LK.getSound('enemyHit').play();
		LK.effects.flashObject(self, 0xffffff, 200);
		if (self.hp <= 0) {
			self.destroyed = true;
		}
	};
	return self;
});
// Enemy Bullet
var EnemyBullet = Container.expand(function () {
	var self = Container.call(this);
	var gfx = self.attachAsset('enemyBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = gfx.width;
	self.height = gfx.height;
	self.speedY = 18;
	self.update = function () {
		self.y += self.speedY;
	};
	return self;
});
// Player Bullet
var PlayerBullet = Container.expand(function () {
	var self = Container.call(this);
	var gfx = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = gfx.width;
	self.height = gfx.height;
	self.speedY = -28;
	self.speedX = 0;
	self.update = function () {
		self.y += self.speedY;
		self.x += self.speedX;
	};
	return self;
});
// Player Ship
var Ship = Container.expand(function () {
	var self = Container.call(this);
	var shipGfx = self.attachAsset('ship', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.width = shipGfx.width;
	self.height = shipGfx.height;
	self.fireCooldown = 0;
	self.fireRate = 30; // ticks between shots
	self.bulletSpeed = -28;
	self.bulletCount = 1;
	self.bulletSpread = 0;
	self.doubleShot = false;
	self.tripleShot = false;
	self.laser = false;
	self.hp = 3;
	self.maxHp = 3;
	self.invulnTicks = 0;
	self.update = function () {
		if (self.fireCooldown > 0) self.fireCooldown--;
		if (self.invulnTicks > 0) {
			self.invulnTicks--;
			shipGfx.alpha = LK.ticks % 8 < 4 ? 0.4 : 1;
		} else {
			shipGfx.alpha = 1;
		}
	};
	self.shoot = function () {
		if (self.fireCooldown > 0) return;
		self.fireCooldown = self.fireRate;
		var shots = [];
		var spread = self.bulletSpread;
		var count = self.bulletCount;
		if (self.tripleShot) {
			count = 3;
			spread = 0.25;
		} else if (self.doubleShot) {
			count = 2;
			spread = 0.18;
		}
		for (var i = 0; i < count; i++) {
			var angle = (i - (count - 1) / 2) * spread;
			var bullet = new PlayerBullet();
			bullet.x = self.x;
			bullet.y = self.y - self.height / 2 - 10;
			bullet.speedY = self.bulletSpeed * Math.cos(angle);
			bullet.speedX = self.bulletSpeed * Math.sin(angle);
			playerBullets.push(bullet);
			game.addChild(bullet);
			shots.push(bullet);
		}
		LK.getSound('shoot').play();
		return shots;
	};
	self.takeDamage = function (amount) {
		if (self.invulnTicks > 0) return;
		self.hp -= amount;
		self.invulnTicks = 60;
		LK.effects.flashObject(self, 0xff0000, 400);
		if (self.hp <= 0) {
			LK.effects.flashScreen(0xff0000, 1000);
			LK.showGameOver();
		}
	};
	return self;
});
// Upgrade Card
var UpgradeCard = Container.expand(function () {
	var self = Container.call(this);
	var highlight = self.attachAsset('upgradeHighlight', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	highlight.visible = false;
	var card = self.attachAsset('upgradeCard', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.text = new Text2('', {
		size: 70,
		fill: 0xFFFFFF
	});
	self.text.anchor.set(0.5, 0.5);
	self.addChild(self.text);
	self.setText = function (t) {
		self.text.setText(t);
	};
	self.setHighlighted = function (v) {
		highlight.visible = v;
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x000000
});

/**** 
* Game Code
****/ 
// Music
// Sound effects
// Upgrade highlight
// Upgrade card
// Enemy bullet
// Bullet (player)
// Enemy
// Ship (player)
// Game state variables
var ship;
var playerBullets = [];
var enemies = [];
var enemyBullets = [];
var wave = 1;
var enemiesToSpawn = 0;
var enemiesDefeated = 0;
var enemiesPerWave = 8;
var waveInProgress = false;
var upgradePending = false;
var upgradeOptions = [];
var upgradeCards = [];
var dragging = false;
var dragOffsetX = 0;
var dragOffsetY = 0;
var score = 0;
var scoreTxt;
var hpTxt;
var waveTxt;
var upgradeGroup;
var lastTouch = {
	x: 0,
	y: 0
};
// Set up background color
game.setBackgroundColor(0x0a0a18);
// Score display
scoreTxt = new Text2('Score: 0', {
	size: 90,
	fill: "#fff"
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// HP display
hpTxt = new Text2('HP: 3', {
	size: 70,
	fill: "#fff"
});
hpTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(hpTxt);
hpTxt.y = 100;
// Wave display
waveTxt = new Text2('Wave: 1', {
	size: 70,
	fill: "#fff"
});
waveTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(waveTxt);
waveTxt.y = 200;
// Upgrade group (overlay)
upgradeGroup = new Container();
upgradeGroup.visible = false;
game.addChild(upgradeGroup);
// Initialize player ship
ship = new Ship();
ship.hp = 100;
ship.maxHp = 100;
game.addChild(ship);
ship.x = 2048 / 2;
ship.y = 2732 - 180;
// Start first wave
startWave();
// Handle dragging ship
game.down = function (x, y, obj) {
	if (upgradePending) return;
	if (pointInShip(x, y)) {
		dragging = true;
		dragOffsetX = ship.x - x;
		dragOffsetY = ship.y - y;
	}
	lastTouch.x = x;
	lastTouch.y = y;
};
game.move = function (x, y, obj) {
	if (upgradePending) {
		// Handle upgrade card selection
		for (var i = 0; i < upgradeCards.length; i++) {
			var card = upgradeCards[i];
			var bounds = getCardBounds(card);
			if (x >= bounds.x && x <= bounds.x + bounds.w && y >= bounds.y && y <= bounds.y + bounds.h) {
				for (var j = 0; j < upgradeCards.length; j++) {
					upgradeCards[j].setHighlighted(j === i);
				}
			}
		}
		lastTouch.x = x;
		lastTouch.y = y;
		return;
	}
	if (dragging) {
		var nx = x + dragOffsetX;
		var ny = y + dragOffsetY;
		// Clamp to screen
		nx = Math.max(ship.width / 2, Math.min(2048 - ship.width / 2, nx));
		ny = Math.max(2732 - 400, Math.min(2732 - ship.height / 2, ny));
		ship.x = nx;
		ship.y = ny;
	}
	lastTouch.x = x;
	lastTouch.y = y;
};
game.up = function (x, y, obj) {
	if (upgradePending) {
		// Check if an upgrade card was selected
		for (var i = 0; i < upgradeCards.length; i++) {
			var card = upgradeCards[i];
			var bounds = getCardBounds(card);
			if (x >= bounds.x && x <= bounds.x + bounds.w && y >= bounds.y && y <= bounds.y + bounds.h) {
				selectUpgrade(i);
				break;
			}
		}
		return;
	}
	dragging = false;
};
// Main game update loop
game.update = function () {
	if (upgradePending) return;
	// Ship update
	ship.update();
	// Ship auto-fire
	if (ship.fireCooldown === 0) {
		ship.shoot();
	}
	// Player bullets
	for (var i = playerBullets.length - 1; i >= 0; i--) {
		var b = playerBullets[i];
		b.update();
		// Remove if off screen
		if (b.y < -b.height) {
			b.destroy();
			playerBullets.splice(i, 1);
			continue;
		}
		// Check collision with enemies
		for (var j = enemies.length - 1; j >= 0; j--) {
			var e = enemies[j];
			if (b.intersects(e)) {
				e.takeDamage(1);
				b.destroy();
				playerBullets.splice(i, 1);
				if (e.hp <= 0 && !e.destroyed) {
					e.destroyed = true;
				}
				break;
			}
		}
	}
	// Enemies
	for (var i = enemies.length - 1; i >= 0; i--) {
		var e = enemies[i];
		e.update();
		// Remove if off screen
		if (e.y > 2732 + e.height) {
			e.destroy();
			enemies.splice(i, 1);
			continue;
		}
		// Remove if destroyed
		if (e.destroyed) {
			score += e.value;
			enemiesDefeated++;
			scoreTxt.setText('Score: ' + score);
			e.destroy();
			enemies.splice(i, 1);
			LK.getSound('hit').play();
			// Check for wave end
			if (enemiesDefeated >= enemiesPerWave) {
				setTimeout(showUpgrade, 600);
			}
			continue;
		}
		// Check collision with ship
		if (e.intersects(ship) && ship.invulnTicks === 0) {
			ship.takeDamage(1);
			e.destroyed = true;
		}
	}
	// Enemy bullets
	for (var i = enemyBullets.length - 1; i >= 0; i--) {
		var eb = enemyBullets[i];
		eb.update();
		if (eb.y > 2732 + eb.height) {
			eb.destroy();
			enemyBullets.splice(i, 1);
			continue;
		}
		if (eb.intersects(ship) && ship.invulnTicks === 0) {
			ship.takeDamage(1);
			eb.destroy();
			enemyBullets.splice(i, 1);
			continue;
		}
	}
	// Spawn enemies
	if (waveInProgress && enemiesToSpawn > 0 && enemies.length < Math.min(5 + wave, 10)) {
		spawnEnemy();
	}
	// Update HP and wave display
	hpTxt.setText('HP: ' + ship.hp);
	waveTxt.setText('Wave: ' + wave);
};
// Start a new wave
function startWave() {
	waveInProgress = true;
	enemiesToSpawn = enemiesPerWave;
	enemiesDefeated = 0;
	waveTxt.setText('Wave: ' + wave);
}
// Spawn a single enemy
function spawnEnemy() {
	var e = new Enemy();
	e.x = 180 + Math.random() * (2048 - 360);
	e.y = -e.height / 2 - 10;
	// Increase difficulty per wave
	e.hp = 1 + Math.floor(wave / 2);
	e.maxHp = e.hp;
	e.speedY = 6 + Math.floor(wave / 3);
	e.shootRate = Math.max(60, 120 - wave * 4 + Math.floor(Math.random() * 40));
	e.value = 1 + Math.floor(wave / 2);
	enemies.push(e);
	game.addChild(e);
	enemiesToSpawn--;
}
// Show upgrade selection
function showUpgrade() {
	if (upgradePending) return;
	upgradePending = true;
	waveInProgress = false;
	upgradeGroup.visible = true;
	// Generate 3 upgrade options
	upgradeOptions = getUpgradeOptions();
	// Remove old cards
	for (var i = 0; i < upgradeCards.length; i++) {
		upgradeCards[i].destroy();
	}
	upgradeCards = [];
	// Layout cards
	var centerX = 2048 / 2;
	var centerY = 2732 / 2;
	var spacing = 700;
	for (var i = 0; i < 3; i++) {
		var card = new UpgradeCard();
		card.x = centerX + (i - 1) * spacing;
		card.y = centerY;
		card.setText(upgradeOptions[i].label);
		card.setHighlighted(false);
		upgradeGroup.addChild(card);
		upgradeCards.push(card);
	}
}
// Select an upgrade
function selectUpgrade(idx) {
	if (!upgradePending) return;
	var upg = upgradeOptions[idx];
	applyUpgrade(upg);
	LK.getSound('upgrade').play();
	// Hide upgrade UI
	for (var i = 0; i < upgradeCards.length; i++) {
		upgradeCards[i].destroy();
	}
	upgradeCards = [];
	upgradeGroup.visible = false;
	upgradePending = false;
	// Next wave
	wave++;
	enemiesPerWave = Math.min(20, 8 + Math.floor(wave * 1.5));
	startWave();
}
// Generate upgrade options
function getUpgradeOptions() {
	var pool = [{
		label: "+1 Max HP",
		apply: function apply() {
			ship.maxHp += 1;
			ship.hp = ship.maxHp;
		}
	}, {
		label: "+1 Bullet per shot",
		apply: function apply() {
			ship.bulletCount = Math.min(5, ship.bulletCount + 1);
		}
	}, {
		label: "Faster Fire Rate",
		apply: function apply() {
			ship.fireRate = Math.max(8, ship.fireRate - 4);
		}
	}, {
		label: "Wider Spread",
		apply: function apply() {
			ship.bulletSpread = Math.min(0.5, ship.bulletSpread + 0.08);
		}
	}, {
		label: "Double Shot",
		apply: function apply() {
			ship.doubleShot = true;
		}
	}, {
		label: "Triple Shot",
		apply: function apply() {
			ship.tripleShot = true;
		}
	}];
	// Remove upgrades already owned
	if (ship.doubleShot) pool = pool.filter(function (u) {
		return u.label !== "Double Shot";
	});
	if (ship.tripleShot) pool = pool.filter(function (u) {
		return u.label !== "Triple Shot";
	});
	// Pick 3 random upgrades
	var options = [];
	var used = {};
	for (var i = 0; i < 3; i++) {
		var idx = Math.floor(Math.random() * pool.length);
		while (used[idx]) idx = (idx + 1) % pool.length;
		used[idx] = true;
		options.push(pool[idx]);
	}
	return options;
}
// Apply upgrade
function applyUpgrade(upg) {
	upg.apply();
}
// Utility: check if point is in ship
function pointInShip(x, y) {
	return x >= ship.x - ship.width / 2 && x <= ship.x + ship.width / 2 && y >= ship.y - ship.height / 2 && y <= ship.y + ship.height / 2;
}
// Utility: get card bounds
function getCardBounds(card) {
	return {
		x: card.x - 310,
		y: card.y - 160,
		w: 620,
		h: 320
	};
}
// Utility: setTimeout using LK
function setTimeout(fn, ms) {
	return LK.setTimeout(fn, ms);
}
// Start music
LK.playMusic('bgmusic', {
	fade: {
		start: 0,
		end: 1,
		duration: 1200
	}
});

===================================================================
--- original.js
+++ change.js
@@ -190,17 +190,17 @@
 
 /**** 
 * Game Code
 ****/ 
-// Game state variables
-// Ship (player)
-// Enemy
-// Bullet (player)
-// Enemy bullet
-// Upgrade card
-// Upgrade highlight
-// Sound effects
 // Music
+// Sound effects
+// Upgrade highlight
+// Upgrade card
+// Enemy bullet
+// Bullet (player)
+// Enemy
+// Ship (player)
+// Game state variables
 var ship;
 var playerBullets = [];
 var enemies = [];
 var enemyBullets = [];