I really enjoyed Final Liberation back in the day and I still have the original CD for it, but it’s been over ten years since I’ve even had it installed on my PC. (And I have no idea if it will even run on newer OS.)
I didn’t have any experience with 40K or the Epic tabletop system that the game was apparently built upon, but it was a decent little beer-and-pretzels wargame, from what I remember. The one big issue with the game, IIRC, was that it only allowed you to use the Imperium and the Orks – no Eldar or Tyranid.