Well I've been playing DwarfFortress for windows, but there's a Linux version that renders using text. It's an ASCII game though and it is EXTREMELY hard to figure out what to do at first, but it is AWESOME (if you're in to that type of stuff).
bay12games.com
*edit: forgot to mention, this game doesn't use much graphics but really punishes the cpu. It can sometimes bring fast machines to their knees.