I've enjoyed playing Eschelon books I and II in the past on Linux. Though single-player RPGs, old school, and beautifully done Book III is now also available for Linux: http://basiliskgames.com/eschalon-book-iii. For those that enjoy single-player RPGs, give it a look. You can download a demo for Linux on the Downloads page.
Others have commented that it is a shorter game. IDK, so far I'm enjoying it immensely and it is worth the price to me There will also be a game editor IIRC, opening the floor for community build games on top of this engine. I already retired my first two character builds that just were too weak