anchor.diff:      player.stop();
   
       if (game.isMobile) {
  -      
  +
         if (leftButton.isDownByTouch()) {
           player.move('left');
         }
         if (rightButton.isDownByTouch()) {
  -        player.move('right');      
  +        player.move('right');
         }
  -      
  +
       } else {
  -      
  +
         if (game.keyboard.isDown(KeyCode.LEFT)) {
           player.move('left');
         }
         if (game.keyboard.isDown(KeyCode.RIGHT)) {
           player.move('right');
         }
  -      
  +
       }
   
   
  
positive.code:     Sound laserSound = game.add.sound("laser");
  
      Sprite bullet;
      bulletTimer = new Timer.periodic(new Duration(milliseconds: 450), (_) {
        if (bullets.any((item) => !item.alive)) {
          bullet = bullets.firstWhere((item) => !item.alive)
              ..x = player.x + player.width ~/ 2
  
negative.code:         laserSound.play();
        }
      });
  
  
      if (game.isMobile) {
  
  