"The year is 2225. The reckless humans have formed a coalition to defend themselves from the rising power of the evil Drengin Empire. The galaxy is about to be set ablaze but there is something far worse out there than each other..." -- From game's website.

Basically it is a game like Civilization or Master of Orion (also set in space) where you must colonize and expand.

Notable features include a very good AI and a nice ship designer.  It is also relatively resolution-independent.