2D Board games
GNU Backgammon is a game of backgammon. The dashboard can be 2D or 3D. Games can be analyzed. The computer opponent is very good.
The developers have used artificial intelligence based on neural networks. They boasts on their site how their artificial intelligence managed to rank in the top 5 of 6,000 players in an international online tournament.
Direct download of version 0.90 for Windows from here: