Anyone familiar with the board game? I just threw together an implementation in Java (humans only). Thinking about trying to do AI, but there are so many possible moves that I don't know if I'll even be able to get 3-ply search.
Unfortunately it's quite difficult. I have ideas, but I think it's a little beyond my meager AI studies. At the beginning of the game there are more possible moves than Go, which has confounded AI researchers for decades. I thought focusing on the endgame might help, but my efforts have yielded very little.
I remember learning how to play Go. Then I heard it was difficult to make a good idea for it, so I thought it'd make a good opponent for my inexperienced self. It completely destroyed me.
I think it'd be cool to have a Smiley themed Freecell game. You know, the card game. Have the smiley characters on the cards. Yeah, it has nothing at all to do with this topic. I just think it'd be cool. I have no idea what the hell Cathedral is anyway.
Re: Cathedral
Never played it, but from reading the Wikipedia article, it sounds interesting. I bet an AI would be difficult though...