Forget the water and flying monkeys! lets play in a huge batch of corn!
http://www.youtube.com/watch?v=0-m1Q...eature=related
...maybe we can have our robots pick up the corn and have to turn it into ethanol in the process of playing the game. That way we can get rid of our bulky batteries, and put combustible materials on the field!
(...i'm pretty sure ethanol's combustible...not positive though)