I looked into this a lot, since my son seems to be under a massive delusion. I got some components working on a the small Zotac. The addition of Steamos to Debian does absolutely nothing in terms of play or graphics components. Sorry, son, but you can't play PC games here.
Right now stos is a dream, a dream about a time when all games will have a native Linux port. That is not this time, but 2 years away. So, forget about your Total Rome, or whatever.
When that happy time comes, then Stos will be there, serving out games, and charging incredible amounts of money. No more inferior free Linux games which is all I play. They won't be Open Source which anybody can steal. These games will be Linux binaries, designed specifically for the hardware of the stos-box. I wish them luck. In the meantime, I will play my Foobillard. :)