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

/**** 
* Classes
****/ 
var Alien = Container.expand(function () {
	var self = Container.call(this);
	var alienGraphics = self.attachAsset('alien', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.health = 3;
	self.speed = 1;
	self.direction = 1;
	self.moveRange = 200;
	self.startX = 0;
	self.active = true;
	self.lastWasHit = false;
	self.takeDamage = function () {
		self.health--;
		if (self.health <= 0) {
			self.active = false;
			LK.getSound('alienDestroy').play();
			// Flash effect before destruction
			tween(alienGraphics, {
				alpha: 0,
				scaleX: 1.5,
				scaleY: 1.5
			}, {
				duration: 300,
				onFinish: function onFinish() {
					self.destroy();
				}
			});
		} else {
			LK.getSound('alienHit').play();
			// Flash red when hit
			LK.effects.flashObject(self, 0xff0000, 200);
		}
	};
	self.update = function () {
		if (!self.active) return;
		// Move alien horizontally
		self.x += self.direction * self.speed;
		// Reverse direction when reaching movement limits
		if (self.x > self.startX + self.moveRange || self.x < self.startX - self.moveRange) {
			self.direction *= -1;
		}
		// Bob up and down slightly
		self.y += Math.sin(LK.ticks * 0.03) * 0.3;
		// Keep alien within screen bounds
		if (self.x < 40) {
			self.x = 40;
			self.direction = 1;
		}
		if (self.x > 2008) {
			self.x = 2008;
			self.direction = -1;
		}
	};
	return self;
});
var Bullet = Container.expand(function () {
	var self = Container.call(this);
	var bulletGraphics = self.attachAsset('bullet', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.speed = -15;
	self.active = true;
	self.update = function () {
		self.y += self.speed;
		// Remove bullet if it goes off screen
		if (self.y < cameraY - 200) {
			self.active = false;
		}
	};
	return self;
});
var Coin = Container.expand(function () {
	var self = Container.call(this);
	var coinGraphics = self.attachAsset('coin', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.collected = false;
	self.rotationSpeed = 0.1;
	self.update = function () {
		// Rotate coin for visual appeal
		coinGraphics.rotation += self.rotationSpeed;
		// Float up and down slightly
		self.y += Math.sin(LK.ticks * 0.05) * 0.5;
	};
	return self;
});
var Dude = Container.expand(function () {
	var self = Container.call(this);
	var dudeGraphics = self.attachAsset('dude', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.velocityY = 0;
	self.velocityX = 0;
	self.isJumping = false;
	self.isOnPlatform = false;
	self.jumpPower = 35;
	self.gravity = 0.8;
	self.maxFallSpeed = 15;
	self.horizontalSpeed = 12;
	self.airResistance = 0.85;
	self.invincible = false;
	self.invincibleTimer = 0;
	self.jump = function () {
		if (self.isOnPlatform) {
			self.velocityY = -self.jumpPower;
			self.isJumping = true;
			self.isOnPlatform = false;
			LK.getSound('jump').play();
		}
	};
	self.update = function () {
		// Auto jump when on platform
		if (self.isOnPlatform) {
			self.jump();
		}
		// Apply gravity
		self.velocityY += self.gravity;
		if (self.velocityY > self.maxFallSpeed) {
			self.velocityY = self.maxFallSpeed;
		}
		// Update position
		self.y += self.velocityY;
		self.x += self.velocityX;
		// Apply continuous horizontal movement while pressed
		if (isPressed && pressedSide !== 0) {
			self.velocityX += pressedSide * self.horizontalSpeed * 0.3;
		}
		// Apply air resistance to horizontal movement
		self.velocityX *= self.airResistance;
		// Handle invincibility timer
		if (self.invincible) {
			self.invincibleTimer--;
			if (self.invincibleTimer <= 0) {
				self.invincible = false;
				dudeGraphics.alpha = 1;
			} else {
				dudeGraphics.alpha = Math.sin(self.invincibleTimer * 0.3) * 0.5 + 0.5;
			}
		}
		// Keep dude on screen horizontally
		if (self.x < 40) self.x = 40;
		if (self.x > 2008) self.x = 2008;
		// Check if fallen off screen
		if (self.y > cameraY + 2732 + 200) {
			LK.showGameOver();
		}
	};
	self.shoot = function () {
		var bullet = new Bullet();
		bullet.x = self.x;
		bullet.y = self.y - 30;
		bullets.push(bullet);
		game.addChild(bullet);
		LK.getSound('shoot').play();
	};
	return self;
});
var Platform = Container.expand(function (type) {
	var self = Container.call(this);
	self.type = type || 'normal';
	self.landed = false;
	self.disappearing = false;
	self.moveDirection = 1;
	self.moveRange = 300;
	self.startX = 0;
	var platformGraphics;
	if (self.type === 'moving') {
		platformGraphics = self.attachAsset('movingPlatform', {
			anchorX: 0.5,
			anchorY: 0.5
		});
	} else if (self.type === 'disappearing') {
		platformGraphics = self.attachAsset('disappearingPlatform', {
			anchorX: 0.5,
			anchorY: 0.5
		});
	} else if (self.type === 'powerup') {
		platformGraphics = self.attachAsset('powerUpPlatform', {
			anchorX: 0.5,
			anchorY: 0.5
		});
	} else {
		platformGraphics = self.attachAsset('platform', {
			anchorX: 0.5,
			anchorY: 0.5
		});
	}
	self.update = function () {
		// Moving platform behavior
		if (self.type === 'moving') {
			self.x += self.moveDirection * 2;
			if (self.x > self.startX + self.moveRange || self.x < self.startX - self.moveRange) {
				self.moveDirection *= -1;
			}
		}
		// Disappearing platform behavior
		if (self.type === 'disappearing' && self.landed && !self.disappearing) {
			self.disappearing = true;
			tween(platformGraphics, {
				alpha: 0
			}, {
				duration: 1000,
				onFinish: function onFinish() {
					self.active = false;
				}
			});
		}
	};
	return self;
});
var Trampoline = Container.expand(function () {
	var self = Container.call(this);
	var trampolineGraphics = self.attachAsset('trampoline', {
		anchorX: 0.5,
		anchorY: 0.5
	});
	self.bounced = false;
	self.active = true;
	self.bounce = function () {
		// Animate trampoline compression and expansion
		tween(trampolineGraphics, {
			scaleY: 0.5
		}, {
			duration: 100,
			easing: tween.easeOut,
			onFinish: function onFinish() {
				tween(trampolineGraphics, {
					scaleY: 1.2
				}, {
					duration: 200,
					easing: tween.bounceOut,
					onFinish: function onFinish() {
						tween(trampolineGraphics, {
							scaleY: 1
						}, {
							duration: 100,
							easing: tween.easeOut
						});
					}
				});
			}
		});
	};
	return self;
});

/**** 
* Initialize Game
****/ 
var game = new LK.Game({
	backgroundColor: 0x87ceeb
});

/**** 
* Game Code
****/ 
var dude = game.addChild(new Dude());
var platforms = [];
var coins = [];
var bullets = [];
var trampolines = [];
var cameraY = 0;
var highestY = 2400;
var lastPlatformY = 2400;
var platformSpacing = 200;
var coinsCollected = 0;
var lastShootTime = 0;
var shootCooldown = 20; // 20 ticks between shots
var aliens = [];
var aliensKilled = 0;
// Create score display
var scoreTxt = new Text2('0', {
	size: 60,
	fill: 0xFFFFFF
});
scoreTxt.anchor.set(0.5, 0);
LK.gui.top.addChild(scoreTxt);
// Create height display
var heightTxt = new Text2('Height: 0m', {
	size: 40,
	fill: 0xFFFFFF
});
heightTxt.anchor.set(1, 0);
heightTxt.x = -20;
heightTxt.y = 20;
LK.gui.topRight.addChild(heightTxt);
// Create coin counter display
var coinTxt = new Text2('Coins: 0', {
	size: 40,
	fill: 0xffd700
});
coinTxt.anchor.set(0, 0);
coinTxt.x = 20;
coinTxt.y = 20;
LK.gui.topLeft.addChild(coinTxt);
// Initialize dude position
dude.x = 1024;
dude.y = 2400;
// Create initial platforms
function createPlatform(x, y, type) {
	var platform = new Platform(type);
	platform.x = x;
	platform.y = y;
	platform.startX = x;
	platform.active = true;
	platforms.push(platform);
	game.addChild(platform);
	return platform;
}
// Create starting platform
createPlatform(1024, 2450, 'normal');
// Generate initial platforms
for (var i = 0; i < 20; i++) {
	generateNextPlatform();
}
function generateNextPlatform() {
	lastPlatformY -= platformSpacing + Math.random() * 100;
	var x = 200 + Math.random() * 1648;
	// Determine platform type based on height
	var type = 'normal';
	var height = Math.abs(lastPlatformY - 2400);
	if (height > 1000) {
		var rand = Math.random();
		if (rand < 0.3) {
			type = 'moving';
		} else if (rand < 0.5) {
			type = 'disappearing';
		} else if (rand < 0.6) {
			type = 'powerup';
		}
	}
	createPlatform(x, lastPlatformY, type);
	// Generate coins near platforms (70% chance)
	if (Math.random() < 0.7) {
		generateCoin(x + (Math.random() - 0.5) * 200, lastPlatformY - 80);
	}
	// Generate trampolines occasionally (20% chance)
	if (Math.random() < 0.2) {
		createTrampoline(x, lastPlatformY - 100);
	}
	// Generate aliens occasionally (30% chance)
	if (Math.random() < 0.3) {
		createAlien(x + (Math.random() - 0.5) * 300, lastPlatformY - 150);
	}
}
function generateCoin(x, y) {
	var coin = new Coin();
	coin.x = x;
	coin.y = y;
	coin.active = true;
	coins.push(coin);
	game.addChild(coin);
}
function createTrampoline(x, y) {
	var trampoline = new Trampoline();
	trampoline.x = x;
	trampoline.y = y;
	trampoline.active = true;
	trampolines.push(trampoline);
	game.addChild(trampoline);
	return trampoline;
}
function createAlien(x, y) {
	var alien = new Alien();
	alien.x = x;
	alien.y = y;
	alien.startX = x;
	alien.active = true;
	aliens.push(alien);
	game.addChild(alien);
	return alien;
}
function updateCamera() {
	var targetY = dude.y - 1800;
	if (targetY < cameraY) {
		cameraY = targetY;
		game.y = -cameraY;
		// Update highest position
		if (dude.y < highestY) {
			highestY = dude.y;
			var height = Math.floor((2400 - highestY) / 10);
			LK.setScore(height);
			scoreTxt.setText(LK.getScore());
			heightTxt.setText('Height: ' + height + 'm');
		}
	}
}
function checkPlatformCollisions() {
	if (dude.velocityY <= 0) return; // Only check when falling
	for (var i = 0; i < platforms.length; i++) {
		var platform = platforms[i];
		if (!platform.active) continue;
		var dudeBottom = dude.y + 40;
		var platformTop = platform.y - 15;
		var platformBottom = platform.y + 15;
		if (dudeBottom >= platformTop && dudeBottom <= platformBottom + 20) {
			if (dude.x >= platform.x - 100 && dude.x <= platform.x + 100) {
				// Landing on platform
				dude.y = platformTop - 40;
				dude.velocityY = 0;
				dude.isOnPlatform = true;
				dude.isJumping = false;
				if (!platform.landed) {
					platform.landed = true;
					LK.getSound('land').play();
					// Handle special platform effects
					if (platform.type === 'powerup') {
						dude.invincible = true;
						dude.invincibleTimer = 300;
						dude.jumpPower = 35;
						LK.getSound('powerup').play();
						// Reset jump power after time
						LK.setTimeout(function () {
							dude.jumpPower = 50;
						}, 3000);
					}
				}
				break;
			}
		}
	}
}
function checkCoinCollisions() {
	for (var i = coins.length - 1; i >= 0; i--) {
		var coin = coins[i];
		if (!coin.active || coin.collected) continue;
		// Check if dude is close enough to collect coin
		var distance = Math.sqrt(Math.pow(dude.x - coin.x, 2) + Math.pow(dude.y - coin.y, 2));
		if (distance < 50) {
			// Collect coin
			coin.collected = true;
			coin.active = false;
			coinsCollected++;
			coinTxt.setText('Coins: ' + coinsCollected);
			LK.getSound('coinCollect').play();
			// Check if player reached 150 coins
			if (coinsCollected >= 150) {
				// Show bravo message
				LK.showYouWin();
			}
			// Remove coin with fade effect
			tween(coin, {
				alpha: 0,
				scaleX: 1.5,
				scaleY: 1.5
			}, {
				duration: 200,
				onFinish: function onFinish() {
					coin.destroy();
					coins.splice(i, 1);
				}
			});
		}
	}
}
function checkTrampolineCollisions() {
	if (dude.velocityY <= 0) return; // Only check when falling
	for (var i = 0; i < trampolines.length; i++) {
		var trampoline = trampolines[i];
		if (!trampoline.active) continue;
		var dudeBottom = dude.y + 40;
		var trampolineTop = trampoline.y - 30;
		var trampolineBottom = trampoline.y + 30;
		if (dudeBottom >= trampolineTop && dudeBottom <= trampolineBottom + 20) {
			if (dude.x >= trampoline.x - 100 && dude.x <= trampoline.x + 100) {
				// Bounce off trampoline with super jump
				dude.velocityY = -60; // Much higher than normal jump
				dude.isJumping = true;
				dude.isOnPlatform = false;
				trampoline.bounce();
				LK.getSound('jump').play();
				break;
			}
		}
	}
}
function checkBulletAlienCollisions() {
	for (var i = bullets.length - 1; i >= 0; i--) {
		var bullet = bullets[i];
		if (!bullet.active) continue;
		for (var j = aliens.length - 1; j >= 0; j--) {
			var alien = aliens[j];
			if (!alien.active) continue;
			// Check collision between bullet and alien
			var distance = Math.sqrt(Math.pow(bullet.x - alien.x, 2) + Math.pow(bullet.y - alien.y, 2));
			if (distance < 50) {
				// Hit detected
				bullet.active = false;
				bullet.destroy();
				bullets.splice(i, 1);
				alien.takeDamage();
				if (!alien.active) {
					aliensKilled++;
					aliens.splice(j, 1);
					// Increase score for killing alien
					LK.setScore(LK.getScore() + 10);
					scoreTxt.setText(LK.getScore());
				}
				break;
			}
		}
	}
}
function cleanupPlatforms() {
	for (var i = platforms.length - 1; i >= 0; i--) {
		var platform = platforms[i];
		if (platform.y > cameraY + 3000 || !platform.active) {
			platform.destroy();
			platforms.splice(i, 1);
		}
	}
}
function cleanupCoins() {
	for (var i = coins.length - 1; i >= 0; i--) {
		var coin = coins[i];
		if (coin.y > cameraY + 3000 || !coin.active) {
			coin.destroy();
			coins.splice(i, 1);
		}
	}
}
function cleanupBullets() {
	for (var i = bullets.length - 1; i >= 0; i--) {
		var bullet = bullets[i];
		if (bullet.y < cameraY - 200 || !bullet.active) {
			bullet.destroy();
			bullets.splice(i, 1);
		}
	}
}
function cleanupTrampolines() {
	for (var i = trampolines.length - 1; i >= 0; i--) {
		var trampoline = trampolines[i];
		if (trampoline.y > cameraY + 3000 || !trampoline.active) {
			trampoline.destroy();
			trampolines.splice(i, 1);
		}
	}
}
function cleanupAliens() {
	for (var i = aliens.length - 1; i >= 0; i--) {
		var alien = aliens[i];
		if (alien.y > cameraY + 3000 || !alien.active) {
			if (alien.active) {
				alien.destroy();
			}
			aliens.splice(i, 1);
		}
	}
}
function generateMorePlatforms() {
	while (lastPlatformY > cameraY - 1000) {
		generateNextPlatform();
	}
}
// Touch controls
var isPressed = false;
var pressedSide = 0; // -1 for left, 1 for right, 0 for center
game.down = function (x, y, obj) {
	dude.jump();
	isPressed = true;
	// Determine which side was pressed
	var screenCenter = 1024; // Half of 2048
	var touchOffset = x - screenCenter;
	if (touchOffset > 50) {
		pressedSide = 1; // Right side
	} else if (touchOffset < -50) {
		pressedSide = -1; // Left side
	} else {
		pressedSide = 0; // Center
	}
	// Shoot when touching center area
	if (Math.abs(touchOffset) <= 50 && LK.ticks - lastShootTime >= shootCooldown) {
		dude.shoot();
		lastShootTime = LK.ticks;
	}
};
game.up = function (x, y, obj) {
	isPressed = false;
	pressedSide = 0;
};
// Main game loop
game.update = function () {
	updateCamera();
	checkPlatformCollisions();
	checkTrampolineCollisions();
	checkCoinCollisions();
	checkBulletAlienCollisions();
	cleanupPlatforms();
	generateMorePlatforms();
	// Remove platforms that are too far down
	if (LK.ticks % 60 === 0) {
		cleanupPlatforms();
		cleanupCoins();
		cleanupBullets();
		cleanupTrampolines();
		cleanupAliens();
	}
};

===================================================================
--- original.js
+++ change.js
@@ -5,8 +5,65 @@
 
 /**** 
 * Classes
 ****/ 
+var Alien = Container.expand(function () {
+	var self = Container.call(this);
+	var alienGraphics = self.attachAsset('alien', {
+		anchorX: 0.5,
+		anchorY: 0.5
+	});
+	self.health = 3;
+	self.speed = 1;
+	self.direction = 1;
+	self.moveRange = 200;
+	self.startX = 0;
+	self.active = true;
+	self.lastWasHit = false;
+	self.takeDamage = function () {
+		self.health--;
+		if (self.health <= 0) {
+			self.active = false;
+			LK.getSound('alienDestroy').play();
+			// Flash effect before destruction
+			tween(alienGraphics, {
+				alpha: 0,
+				scaleX: 1.5,
+				scaleY: 1.5
+			}, {
+				duration: 300,
+				onFinish: function onFinish() {
+					self.destroy();
+				}
+			});
+		} else {
+			LK.getSound('alienHit').play();
+			// Flash red when hit
+			LK.effects.flashObject(self, 0xff0000, 200);
+		}
+	};
+	self.update = function () {
+		if (!self.active) return;
+		// Move alien horizontally
+		self.x += self.direction * self.speed;
+		// Reverse direction when reaching movement limits
+		if (self.x > self.startX + self.moveRange || self.x < self.startX - self.moveRange) {
+			self.direction *= -1;
+		}
+		// Bob up and down slightly
+		self.y += Math.sin(LK.ticks * 0.03) * 0.3;
+		// Keep alien within screen bounds
+		if (self.x < 40) {
+			self.x = 40;
+			self.direction = 1;
+		}
+		if (self.x > 2008) {
+			self.x = 2008;
+			self.direction = -1;
+		}
+	};
+	return self;
+});
 var Bullet = Container.expand(function () {
 	var self = Container.call(this);
 	var bulletGraphics = self.attachAsset('bullet', {
 		anchorX: 0.5,
@@ -221,8 +278,10 @@
 var platformSpacing = 200;
 var coinsCollected = 0;
 var lastShootTime = 0;
 var shootCooldown = 20; // 20 ticks between shots
+var aliens = [];
+var aliensKilled = 0;
 // Create score display
 var scoreTxt = new Text2('0', {
 	size: 60,
 	fill: 0xFFFFFF
@@ -291,8 +350,12 @@
 	// Generate trampolines occasionally (20% chance)
 	if (Math.random() < 0.2) {
 		createTrampoline(x, lastPlatformY - 100);
 	}
+	// Generate aliens occasionally (30% chance)
+	if (Math.random() < 0.3) {
+		createAlien(x + (Math.random() - 0.5) * 300, lastPlatformY - 150);
+	}
 }
 function generateCoin(x, y) {
 	var coin = new Coin();
 	coin.x = x;
@@ -309,8 +372,18 @@
 	trampolines.push(trampoline);
 	game.addChild(trampoline);
 	return trampoline;
 }
+function createAlien(x, y) {
+	var alien = new Alien();
+	alien.x = x;
+	alien.y = y;
+	alien.startX = x;
+	alien.active = true;
+	aliens.push(alien);
+	game.addChild(alien);
+	return alien;
+}
 function updateCamera() {
 	var targetY = dude.y - 1800;
 	if (targetY < cameraY) {
 		cameraY = targetY;
@@ -413,8 +486,35 @@
 			}
 		}
 	}
 }
+function checkBulletAlienCollisions() {
+	for (var i = bullets.length - 1; i >= 0; i--) {
+		var bullet = bullets[i];
+		if (!bullet.active) continue;
+		for (var j = aliens.length - 1; j >= 0; j--) {
+			var alien = aliens[j];
+			if (!alien.active) continue;
+			// Check collision between bullet and alien
+			var distance = Math.sqrt(Math.pow(bullet.x - alien.x, 2) + Math.pow(bullet.y - alien.y, 2));
+			if (distance < 50) {
+				// Hit detected
+				bullet.active = false;
+				bullet.destroy();
+				bullets.splice(i, 1);
+				alien.takeDamage();
+				if (!alien.active) {
+					aliensKilled++;
+					aliens.splice(j, 1);
+					// Increase score for killing alien
+					LK.setScore(LK.getScore() + 10);
+					scoreTxt.setText(LK.getScore());
+				}
+				break;
+			}
+		}
+	}
+}
 function cleanupPlatforms() {
 	for (var i = platforms.length - 1; i >= 0; i--) {
 		var platform = platforms[i];
 		if (platform.y > cameraY + 3000 || !platform.active) {
@@ -449,8 +549,19 @@
 			trampolines.splice(i, 1);
 		}
 	}
 }
+function cleanupAliens() {
+	for (var i = aliens.length - 1; i >= 0; i--) {
+		var alien = aliens[i];
+		if (alien.y > cameraY + 3000 || !alien.active) {
+			if (alien.active) {
+				alien.destroy();
+			}
+			aliens.splice(i, 1);
+		}
+	}
+}
 function generateMorePlatforms() {
 	while (lastPlatformY > cameraY - 1000) {
 		generateNextPlatform();
 	}
@@ -486,14 +597,16 @@
 	updateCamera();
 	checkPlatformCollisions();
 	checkTrampolineCollisions();
 	checkCoinCollisions();
+	checkBulletAlienCollisions();
 	cleanupPlatforms();
 	generateMorePlatforms();
 	// Remove platforms that are too far down
 	if (LK.ticks % 60 === 0) {
 		cleanupPlatforms();
 		cleanupCoins();
 		cleanupBullets();
 		cleanupTrampolines();
+		cleanupAliens();
 	}
 };
\ No newline at end of file