It's his game Really Bad Chess. The game is similar to a normal chess game, except that instead of the AI getting harder as you advance through the game, the AI

It's his game Really Bad Chess. The game is similar to a normal chess game, except that instead of the AI getting harder as you advance through the game, the AI gets better pieces (and you get worse pieces). It's a fresh take on chess and is well worth trying. You end up ranking to a level where every game is challenging.