This Tic Tac Toe game that has four difficulty levels Easy, Medium, Hard, and Impossible.
You can also play two player games Via link or you can have two people on the same calculator.

If you have any comments, or would like to report a bug E-mail Ash-Ketchum@nc.rr.com (I made the e-mail adress two years ago when I didn't know any better)
Also E-mail me if you find that it isn't Impossible to beat Impossible mode without hacking the game.