Hi, I'm one of the manager of this project. I have to say that any project has expenses for development, advertising, promotion and etc. So that is the reason it can't be 0.001BTC for a square. Actually the total income of the house will be about 15% from this game after all expenses.
About escrow it's really good idea. Please recommend us some trusted escrow to put there 1BTC prize.
You can go with MinerJones, OgNasty, DarkStar_, krogothmanhattan, Hhampuz. These guys are really good at what they do. They are long term and trusted guys in the forum. They can hold the 1
BTC for you.
An escrow will give you more business then you are thinking of.
Good luck.