anchor.diff:  
       _gameLayer = new Node();
       this.addChild(_gameLayer);
  -
  -    // Add some asteroids to the game world
  -    for (int i = 0; i < 5; i++) {
  -      addAsteroid(AsteroidSize.large);
  -    }
  -    for (int i = 0; i < 5; i++) {
  -      addAsteroid(AsteroidSize.medium);
  -    }
  -
       // Add ship
       addShip();
   
  
positive.code:           // Remove asteroid
            asteroid.removeFromParent();
            _asteroids.removeAt(j);
            break;
          }
        }
  
negative.code:     // Move objects to center camera and warp objects around the edges
      centerCamera();
      warpObjects();
  
      // Check for level up
      if (_asteroids.length == 0) {
        _currentLevel++;
        setupLevel(_currentLevel);
      }
  
      // Update shield
      if (_numFrames > _numFramesShieldActive) _shield.visible = false;
  