I recenty finished a 2-player game, based on a spider and a fly moving around a 3x3 grid.
I'm pretty sure everything is working, so if anyone would like a copy to try it out then just reply here or IM me in-world and I'll send you one.
http://lucius-games.blogspot.com/2007/05/spider-fly-final-graphics.html
Game-play is split into two phases; first you have 10 seconds to enter some moves (using a HUD), then after 10 seconds the actions are played out. This process repeats until the spider catches the fly (both in the same grid square). The twist is that the role of the spider and the fly switches randomly between turns.