there could be multiplayer race. you could fill in holes in your own lane as fast as u can, then start whenever and try to get to the end before anyone else.
Well u could do the Race thing but why stop there when u could make your own course and send it to them or like have your profile sent to the other DS.
Is there going to be a multiplayer mode? I don't know how it would work, but I was wondering if multiple humans could play at the same time.