It would be cool to have other modes you could play like:
Two human players (if you wanted to play with someone else at the same computer)
Teams where you pick another color as your teammate. In this mode you and your teammate act almost as one - e.g, you can't jump your teammate's marble and you can't capture your teammate's marbles.
Online multiplayer - this would be awesome but I have no idea where to start with this.
It would be cool to have other modes you could play like: