Vincent Baker has just completed Mechaton, his Lego mecha game. I had the opportunity to play this on Friday, and it was great fun. Fairly snappy play, but the ability to break bits off your mechs when they took damage was much fun. Besides, purchasing a PDF download of the game is only $6.
If you like the idea of building little Lego robots and then blowing each other up, you really should check out this game.