Phoronix is giving away some copies of Unigine's OilRush, you can participate over here.
"Unigine's OilRush game will be making its debut in June, but
those who pre-order now have beta access to this Linux and Windows game
that is a real-time strategy and offers impressive graphics.
Fortunately, if you're short on change, we're giving away a few copies
of this first game by Unigine Corp."