From the FAQ
Q: What’s this revenue share?
A: You get a percentage of what we make(....)
Have you decided what percentage yet, and is the revenue share of net or gross reciepts for the game?
$500 is maybe 2 days work for an average programmer in the US, I can't see a commercial quality game being done in two days even if that didn't include graphics and music. So it is very important to anyone considering working on a game for overloaded to know the details of the revenue share deal up front.