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

/**** 
* Classes
****/ 
var EnemyBullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('enemyBullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 6;
	self.velocityX = 0;
	self.velocityY = 0;
	self.setVelocity = function (vx, vy) {
		self.velocityX = vx;
		self.velocityY = vy;
	};
	self.update = function () {
		self.x += self.velocityX;
		self.y += self.velocityY;
	};
	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 PlayerTank = Container.expand(function () {
	var self = Container.call(this);
	var tankGraphics = self.attachAsset('playerTank', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 8;
	self.fireRate = 15;
	self.fireTimer = 0;
	self.update = function () {
		if (self.fireTimer > 0) {
			self.fireTimer--;
		}
	};
	self.canFire = function () {
		return self.fireTimer <= 0;
	};
	self.fire = function () {
		if (self.canFire()) {
			self.fireTimer = self.fireRate;
			return true;
		}
		return false;
	};
	return self;
});
var SmallUFO = Container.expand(function () {
	var self = Container.call(this);
	var smallUfoGraphics = self.attachAsset('ufo', {
		anchorX: 0.5,
		anchorY: 0.5,
		scaleX: 0.3,
		scaleY: 0.3
	});
	self.speed = 3;
	self.direction = Math.random() < 0.5 ? -1 : 1;
	self.fireTimer = 0;
	self.fireRate = 120;
	self.update = function () {
		self.x += self.speed * self.direction;
		if (self.x > 1900 || self.x < 148) {
			self.direction *= -1;
		}
		self.fireTimer++;
		if (self.fireTimer >= self.fireRate) {
			self.fireTimer = 0;
			return true;
		}
		return false;
	};
	return self;
});
var Spaceship = Container.expand(function () {
	var self = Container.call(this);
	var spaceshipGraphics = self.attachAsset('spaceship', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 2;
	self.direction = 1;
	self.deployTimer = 0;
	self.deployRate = 180;
	self.movePattern = Math.random() < 0.5 ? 'horizontal' : 'diagonal';
	self.update = function () {
		if (self.movePattern === 'horizontal') {
			self.x += self.speed * self.direction;
			if (self.x > 1900 || self.x < 148) {
				self.direction *= -1;
			}
		} else {
			self.x += self.speed * self.direction;
			self.y += self.speed * 0.5;
			if (self.x > 1900 || self.x < 148) {
				self.direction *= -1;
			}
		}
		self.deployTimer++;
		if (self.deployTimer >= self.deployRate) {
			self.deployTimer = 0;
			return true;
		}
		return false;
	};
	return self;
});
var UFO = Container.expand(function () {
	var self = Container.call(this);
	var ufoGraphics = self.attachAsset('ufo', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = 2;
	self.direction = 1;
	self.verticalSpeed = 0.5;
	self.fireTimer = 0;
	self.fireRate = 80;
	self.isMoving = false;
	self.hitCount = 0;
	self.maxHits = 30;
	self.level = 1;
	self.startMovement = function () {
		if (!self.isMoving) {
			self.isMoving = true;
			self.moveLeftRight();
		}
	};
	self.moveLeftRight = function () {
		var targetX = self.direction > 0 ? 1600 : 448;
		tween(self, {
			x: targetX
		}, {
			duration: 4000,
			easing: tween.linear,
			onFinish: function onFinish() {
				self.direction *= -1;
				self.moveLeftRight();
			}
		});
	};
	self.update = function () {
		if (!self.isMoving) {
			self.startMovement();
		}
		self.fireTimer++;
		if (self.fireTimer >= self.fireRate) {
			self.fireTimer = 0;
			return 'fire';
		}
		// Deploy spaceship every 240 frames (4 seconds)
		if (self.fireTimer % 240 === 0) {
			return 'deploy';
		}
		return false;
	};
	self.hit = function () {
		self.hitCount++;
		if (self.hitCount >= self.maxHits) {
			// UFO dies after 21 hits
			return 'destroy';
		}
		return false; // UFO not dead yet
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x000033
});

/**** 
* Game Code
****/ 
var background = LK.getAsset('background', {
	anchorX: 0,
	anchorY: 0,
	x: 0,
	y: 0,
	width: 2048,
	height: 2732
});
game.addChild(background);
var player = new PlayerTank();
player.x = 1024;
player.y = 200;
game.addChild(player);
var playerBullets = [];
var spaceships = [];
var ufos = [];
var smallUfos = [];
var enemyBullets = [];
var spawnTimer = 0;
var spawnRate = 120;
var ufoSpawnTimer = 0;
var ufoSpawnRate = 600;
var hasActiveUFO = false;
var enemyFireTimer = 0;
var enemyFireRate = 90;
var currentLevel = 1;
var maxLevel = 10;
var enemiesKilledThisLevel = 0;
var enemiesToKillForNextLevel = 1;
var playerLives = 3;
var maxLives = 3;
var lastScoreMilestone = 0;
var scoreTxt = new Text2('Score: 0', {
	size: 60,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
var levelTxt = new Text2('Level: 1', {
	size: 60,
	fill: 0xFFFF00
});
levelTxt.anchor.set(0.5, 0);
levelTxt.x = 0;
levelTxt.y = 80;
LK.gui.top.addChild(levelTxt);
var lifeHearts = [];
for (var lifeIndex = 0; lifeIndex < maxLives; lifeIndex++) {
	var heart = new Text2('♥', {
		size: 80,
		fill: 0xFF0000
	});
	heart.anchor.set(0, 1);
	heart.x = 120 + lifeIndex * 90;
	heart.y = -20;
	lifeHearts.push(heart);
	LK.gui.bottomLeft.addChild(heart);
}
function updateScore() {
	scoreTxt.setText('Score: ' + LK.getScore());
}
function updateLevel() {
	levelTxt.setText('Level: ' + currentLevel);
}
function updateLives() {
	for (var i = 0; i < maxLives; i++) {
		if (i < playerLives) {
			lifeHearts[i].alpha = 1.0;
		} else {
			lifeHearts[i].alpha = 0.3;
		}
	}
}
function checkLevelProgression() {
	var shouldLevelUp = false;
	// Check if we should level up based on UFO kills only
	if (enemiesKilledThisLevel >= enemiesToKillForNextLevel) {
		if (currentLevel < maxLevel) {
			shouldLevelUp = true;
			currentLevel++;
			enemiesKilledThisLevel = 0;
			enemiesToKillForNextLevel = 1; // Only need 1 UFO kill to advance
		}
	}
	if (shouldLevelUp) {
		if (currentLevel >= maxLevel) {
			// Player completed all levels
			LK.showYouWin();
		} else {
			updateLevel();
			// Increase difficulty based on level
			spawnRate = Math.max(30, 120 - (currentLevel - 1) * 10);
			enemyFireRate = Math.max(20, 90 - (currentLevel - 1) * 8);
			// Flash screen to indicate level up
			LK.effects.flashScreen(0x00ffff, 1000); // Cyan flash for level up
		}
	}
}
function spawnSpaceship() {
	var spaceship = new Spaceship();
	// If there's an active UFO, spawn from its position
	if (hasActiveUFO && ufos.length > 0) {
		spaceship.x = ufos[0].x;
		spaceship.y = ufos[0].y + 100; // Spawn slightly below UFO
	} else {
		spaceship.x = Math.random() * 1800 + 124;
		spaceship.y = -50;
	}
	spaceships.push(spaceship);
	game.addChild(spaceship);
}
function spawnUFO() {
	if (!hasActiveUFO && ufos.length === 0) {
		var ufo = new UFO();
		ufo.x = 1024;
		ufo.y = 200;
		// Make subsequent UFOs stronger
		if (currentLevel > 1) {
			ufo.level = Math.min(currentLevel, 5);
			ufo.fireRate = Math.max(20, 80 - (ufo.level - 1) * 15);
			var newScale = 1 + (ufo.level - 1) * 0.2;
			ufo.scaleX = newScale;
			ufo.scaleY = newScale;
		}
		ufos.push(ufo);
		game.addChild(ufo);
		hasActiveUFO = true;
	}
}
function deploySmallUFO(fromX, fromY) {
	var smallUfo = new SmallUFO();
	smallUfo.x = fromX;
	smallUfo.y = fromY;
	smallUfos.push(smallUfo);
	game.addChild(smallUfo);
	LK.getSound('uavDeploy').play();
}
function clearAllEnemiesAndStartNewLevel() {
	// Destroy all spaceships
	for (var i = spaceships.length - 1; i >= 0; i--) {
		spaceships[i].destroy();
	}
	spaceships = [];
	// Destroy all small UFOs
	for (var j = smallUfos.length - 1; j >= 0; j--) {
		smallUfos[j].destroy();
	}
	smallUfos = [];
	// Destroy all UFOs
	for (var k = ufos.length - 1; k >= 0; k--) {
		ufos[k].destroy();
	}
	ufos = [];
	hasActiveUFO = false;
	// Destroy all enemy bullets
	for (var l = enemyBullets.length - 1; l >= 0; l--) {
		enemyBullets[l].destroy();
	}
	enemyBullets = [];
	// Don't automatically advance level - let normal progression handle it
	// Just check if we should advance based on current kills
	checkLevelProgression();
}
function fireEnemyBullet(fromX, fromY) {
	var bullet = new EnemyBullet();
	bullet.x = fromX;
	bullet.y = fromY;
	bullet.setVelocity(0, 6);
	enemyBullets.push(bullet);
	game.addChild(bullet);
}
game.down = function (x, y, obj) {
	// Move player to touch position
	player.x = x;
	// Keep player within screen boundaries
	if (player.x > 1988) {
		player.x = 1988;
	}
	if (player.x < 60) {
		player.x = 60;
	}
	// Shooting now handled by up event for better control
};
game.move = function (x, y, obj) {
	// Move player horizontally based on touch/mouse position
	player.x = x;
	// Keep player within screen boundaries
	if (player.x > 1988) {
		player.x = 1988;
	}
	if (player.x < 60) {
		player.x = 60;
	}
};
game.up = function (x, y, obj) {
	// Fire bullet when releasing touch/click
	if (player.fire()) {
		var bullet = new PlayerBullet();
		bullet.x = player.x;
		bullet.y = player.y - 40;
		playerBullets.push(bullet);
		game.addChild(bullet);
		LK.getSound('playerShoot').play();
	}
};
game.update = function () {
	// Check for score milestones to award extra lives
	var currentScore = LK.getScore();
	var currentMilestone2500 = Math.floor(currentScore / 2500);
	var currentMilestone5000 = Math.floor(currentScore / 5000);
	if (currentMilestone2500 > lastScoreMilestone) {
		// Award extra life for reaching 2500 point milestone
		if (playerLives < maxLives) {
			playerLives++;
			updateLives();
			LK.effects.flashScreen(0x00ff00, 1000); // Green flash for life reward
		}
		lastScoreMilestone = currentMilestone2500;
	}
	// Check for 5000 point milestones
	if (currentMilestone5000 > 0 && currentScore >= currentMilestone5000 * 5000 && currentScore - 5000 < (currentMilestone5000 - 1) * 5000) {
		// Award extra life for reaching 5000 point milestone
		if (playerLives < maxLives) {
			playerLives++;
			updateLives();
			LK.effects.flashScreen(0x00ff00, 1000); // Green flash for life reward
		}
	}
	// Player movement is now handled by touch/mouse controls
	// Spawn spaceships
	spawnTimer++;
	if (spawnTimer >= spawnRate) {
		spawnTimer = 0;
		spawnSpaceship();
	}
	// Spawn UFOs
	ufoSpawnTimer++;
	if (ufoSpawnTimer >= ufoSpawnRate && !hasActiveUFO) {
		ufoSpawnTimer = 0;
		spawnUFO();
	}
	// Difficulty is now controlled by level progression
	// Player auto-fire removed - now controlled by touch
	// Enemy firing
	enemyFireTimer++;
	if (enemyFireTimer >= enemyFireRate) {
		enemyFireTimer = 0;
		if (spaceships.length > 0) {
			var randomSpaceship = spaceships[Math.floor(Math.random() * spaceships.length)];
			fireEnemyBullet(randomSpaceship.x, randomSpaceship.y);
		}
	}
	// Update player bullets
	for (var i = playerBullets.length - 1; i >= 0; i--) {
		var bullet = playerBullets[i];
		if (bullet.lastY === undefined) bullet.lastY = bullet.y;
		if (bullet.lastY >= -20 && bullet.y < -20) {
			bullet.destroy();
			playerBullets.splice(i, 1);
			continue;
		}
		bullet.lastY = bullet.y;
	}
	// Update spaceships
	for (var j = spaceships.length - 1; j >= 0; j--) {
		var spaceship = spaceships[j];
		if (spaceship.lastY === undefined) spaceship.lastY = spaceship.y;
		if (spaceship.deployCount === undefined) spaceship.deployCount = 0;
		var shouldDeploy = spaceship.update();
		if (shouldDeploy) {
			deploySmallUFO(spaceship.x, spaceship.y);
		}
		if (spaceship.lastY < 2732 && spaceship.y >= 2732) {
			playerLives--;
			updateLives();
			spaceship.destroy();
			spaceships.splice(j, 1);
			LK.effects.flashScreen(0xff0000, 1000);
			if (playerLives <= 0) {
				LK.showGameOver();
				return;
			}
			continue;
		}
		spaceship.lastY = spaceship.y;
	}
	// Update small UFOs
	for (var su = smallUfos.length - 1; su >= 0; su--) {
		var smallUfo = smallUfos[su];
		if (smallUfo.lastY === undefined) smallUfo.lastY = smallUfo.y;
		var shouldFire = smallUfo.update();
		if (shouldFire) {
			fireEnemyBullet(smallUfo.x, smallUfo.y);
		}
		if (smallUfo.lastY < 2732 && smallUfo.y >= 2732) {
			playerLives--;
			updateLives();
			smallUfo.destroy();
			smallUfos.splice(su, 1);
			LK.effects.flashScreen(0xff0000, 1000);
			if (playerLives <= 0) {
				LK.showGameOver();
				return;
			}
			continue;
		}
		smallUfo.lastY = smallUfo.y;
	}
	// Update UFOs - only one UFO at a time
	if (ufos.length > 0) {
		var ufo = ufos[0];
		if (ufo.lastY === undefined) ufo.lastY = ufo.y;
		var action = ufo.update();
		if (action === 'fire') {
			fireEnemyBullet(ufo.x, ufo.y);
		} else if (action === 'deploy') {
			spawnSpaceship();
		}
		if (ufo.lastY < 2732 && ufo.y >= 2732) {
			playerLives--;
			updateLives();
			ufo.destroy();
			ufos.splice(0, 1);
			hasActiveUFO = false;
			LK.effects.flashScreen(0xff0000, 1000);
			if (playerLives <= 0) {
				LK.showGameOver();
				return;
			}
		}
		ufo.lastY = ufo.y;
	}
	// Update enemy bullets
	for (var l = enemyBullets.length - 1; l >= 0; l--) {
		var enemyBullet = enemyBullets[l];
		if (enemyBullet.lastY === undefined) enemyBullet.lastY = enemyBullet.y;
		if (enemyBullet.lastX === undefined) enemyBullet.lastX = enemyBullet.x;
		// Destroy bullet if it goes off-screen (top)
		if (enemyBullet.lastY >= -20 && enemyBullet.y < -20) {
			enemyBullet.destroy();
			enemyBullets.splice(l, 1);
			continue;
		}
		// Destroy bullet if it goes off-screen (bottom)
		if (enemyBullet.lastY < 2732 && enemyBullet.y >= 2732) {
			enemyBullet.destroy();
			enemyBullets.splice(l, 1);
			continue;
		}
		// Destroy bullet if it goes off-screen (left side)
		if (enemyBullet.lastX >= 0 && enemyBullet.x < 0) {
			enemyBullet.destroy();
			enemyBullets.splice(l, 1);
			continue;
		}
		// Destroy bullet if it goes off-screen (right side)
		if (enemyBullet.lastX <= 2048 && enemyBullet.x > 2048) {
			enemyBullet.destroy();
			enemyBullets.splice(l, 1);
			continue;
		}
		enemyBullet.lastY = enemyBullet.y;
		enemyBullet.lastX = enemyBullet.x;
	}
	// Collision detection - Player bullets vs Spaceships
	for (var m = playerBullets.length - 1; m >= 0; m--) {
		var pBullet = playerBullets[m];
		for (var n = spaceships.length - 1; n >= 0; n--) {
			var ship = spaceships[n];
			if (pBullet.intersects(ship)) {
				LK.setScore(LK.getScore() + 100);
				updateScore();
				LK.getSound('enemyDestroy').play();
				// Spawn 3 enemy bullets when spaceship explodes
				for (var explosionBullet = 0; explosionBullet < 3; explosionBullet++) {
					var bullet = new EnemyBullet();
					bullet.x = ship.x;
					bullet.y = ship.y;
					// Spread bullets in different directions
					var angle = (explosionBullet * 60 - 60) * Math.PI / 180; // -60, 0, 60 degrees
					var bulletSpeed = 4;
					bullet.setVelocity(Math.sin(angle) * bulletSpeed, Math.cos(angle) * bulletSpeed);
					enemyBullets.push(bullet);
					game.addChild(bullet);
				}
				// Create explosion effect
				tween(ship, {
					scaleX: 2,
					scaleY: 2,
					alpha: 0,
					tint: 0xff4400
				}, {
					duration: 500,
					easing: tween.easeOut,
					onFinish: function onFinish() {
						ship.destroy();
					}
				});
				pBullet.destroy();
				playerBullets.splice(m, 1);
				spaceships.splice(n, 1);
				break;
			}
		}
	}
	// Collision detection - Player bullets vs Small UFOs
	for (var su2 = playerBullets.length - 1; su2 >= 0; su2--) {
		var pBullet4 = playerBullets[su2];
		for (var su3 = smallUfos.length - 1; su3 >= 0; su3--) {
			var smallUfo2 = smallUfos[su3];
			if (pBullet4.intersects(smallUfo2)) {
				LK.setScore(LK.getScore() + 75);
				updateScore();
				LK.getSound('enemyDestroy').play();
				// Create explosion effect
				tween(smallUfo2, {
					scaleX: 0.6,
					scaleY: 0.6,
					alpha: 0,
					tint: 0xff4400
				}, {
					duration: 400,
					easing: tween.easeOut,
					onFinish: function onFinish() {
						smallUfo2.destroy();
					}
				});
				pBullet4.destroy();
				playerBullets.splice(su2, 1);
				smallUfos.splice(su3, 1);
				break;
			}
		}
	}
	// Collision detection - Player bullets vs UFOs - single UFO
	for (var t = playerBullets.length - 1; t >= 0; t--) {
		var pBullet3 = playerBullets[t];
		if (ufos.length > 0) {
			var ufo2 = ufos[0];
			if (pBullet3.intersects(ufo2)) {
				var hitResult = ufo2.hit();
				if (hitResult === 'destroy') {
					// UFO dies - give big score and level up
					LK.setScore(LK.getScore() + 1000);
					updateScore();
					enemiesKilledThisLevel++;
					checkLevelProgression();
					LK.getSound('enemyDestroy').play();
					// Create explosion effect
					tween(ufo2, {
						scaleX: 3,
						scaleY: 3,
						alpha: 0,
						tint: 0xff4400
					}, {
						duration: 1000,
						easing: tween.easeOut,
						onFinish: function onFinish() {
							ufo2.destroy();
							clearAllEnemiesAndStartNewLevel();
						}
					});
					ufos.splice(0, 1);
					hasActiveUFO = false;
				} else {
					LK.setScore(LK.getScore() + 10);
					updateScore();
					LK.getSound('enemyDestroy').play();
				}
				// Create hit effect
				tween(ufo2, {
					tint: 0xff0066
				}, {
					duration: 200,
					easing: tween.easeOut,
					onFinish: function onFinish() {
						ufo2.tint = 0xffffff;
					}
				});
				pBullet3.destroy();
				playerBullets.splice(t, 1);
				break;
			}
		}
	}
	// Collision detection - Enemy bullets vs Player
	for (var q = enemyBullets.length - 1; q >= 0; q--) {
		var eBullet = enemyBullets[q];
		if (eBullet.intersects(player)) {
			playerLives--;
			updateLives();
			eBullet.destroy();
			enemyBullets.splice(q, 1);
			LK.effects.flashScreen(0xff0000, 1000);
			if (playerLives <= 0) {
				LK.showGameOver();
				return;
			}
			break;
		}
	}
	// Collision detection - Spaceships vs Player
	for (var s = spaceships.length - 1; s >= 0; s--) {
		var ship2 = spaceships[s];
		if (ship2.intersects(player)) {
			playerLives--;
			updateLives();
			ship2.destroy();
			spaceships.splice(s, 1);
			LK.effects.flashScreen(0xff0000, 1000);
			if (playerLives <= 0) {
				LK.showGameOver();
				return;
			}
			break;
		}
	}
	// Collision detection - Small UFOs vs Player
	for (var su4 = smallUfos.length - 1; su4 >= 0; su4--) {
		var smallUfo3 = smallUfos[su4];
		if (smallUfo3.intersects(player)) {
			playerLives--;
			updateLives();
			smallUfo3.destroy();
			smallUfos.splice(su4, 1);
			LK.effects.flashScreen(0xff0000, 1000);
			if (playerLives <= 0) {
				LK.showGameOver();
				return;
			}
			break;
		}
	}
	// Collision detection - Player bullets vs Enemy bullets
	for (var pb = playerBullets.length - 1; pb >= 0; pb--) {
		var playerBullet = playerBullets[pb];
		for (var eb = enemyBullets.length - 1; eb >= 0; eb--) {
			var enemyBullet = enemyBullets[eb];
			if (playerBullet.intersects(enemyBullet)) {
				// Destroy both bullets
				playerBullet.destroy();
				enemyBullet.destroy();
				playerBullets.splice(pb, 1);
				enemyBullets.splice(eb, 1);
				break;
			}
		}
	}
	// Collision detection - UFOs vs Player - single UFO
	if (ufos.length > 0) {
		var ufo3 = ufos[0];
		if (ufo3.intersects(player)) {
			playerLives--;
			updateLives();
			ufo3.destroy();
			ufos.splice(0, 1);
			hasActiveUFO = false;
			LK.effects.flashScreen(0xff0000, 1000);
			if (playerLives <= 0) {
				LK.showGameOver();
				return;
			}
		}
	}
};
LK.playMusic('battleMusic');

===================================================================
--- original.js
+++ change.js
@@ -202,9 +202,9 @@
 });
 game.addChild(background);
 var player = new PlayerTank();
 player.x = 1024;
-player.y = 2600;
+player.y = 200;
 game.addChild(player);
 var playerBullets = [];
 var spaceships = [];
 var ufos = [];