A bunch of people created a chess system that runs on the EVM: here.
I'd like to make a similar game of battleships but there seems to be an apparent difference. In battleships, you can't know what the other person's board looks like whereas in chess, nothing is hidden.
This answer explains quite well why the data is irrevocably public. What I'd like to know is, how easy would it be for a player to cheat by, for example, looking through the blockchain?