anchor.diff:  
     State _context;
   
  +  num _accelerationScale = 0;
  +
     /**
      * Does the sprite move?
      */
  
positive.code:     if (!mainDirection.isZero) mainDirection = zeroVector;
    }
  
  }
  
negative.code: 
    bool checkWorldBounds = false;
  
    /**
     * Kill Sprite if it's out of the world's bounds.
     */
    bool killOutOfBounds = false;
  
    /**
  