it would be so cool to have multiplayer modes, but when you think about it, you need to have the community know where the connection is and be able to secure system so that nobody abuses it.
If you wanted to take it further, you can setup a database structure with user login and a server setup with maybe IRC connection or create our own lobby for all the players to know.
Another idea to take it even further, you could have a highscore submit option in handy.
These are just some ideas I'm throwing in.