Drodin has ported the classic Linux game, Extreme Tux Racer, to the PlayBook. The game is open source but they are charging $1.99 for it in App World. Either way the classic Linux game is quite fun on the PlayBook even in beta form.
Read the full thing at http://www.berryreview.com/2011/11/02/extreme-tux-racer-game-brings-the-linux-mascot-to-the-playbook/
Every time I open it up, there are full blast audio adds, so just jump to https://appworld.blackberry.com/webstore/content/61940 in App World