This is essentially a mod of Crimson moon see index
Instead of being attacked by a vampire or werewolf and raised as undead, instead your recruited into the armed forces as one of a number of specialist troop types to join the war against the aliens who have invaded the earth.
The outer area, rather than being full of fantasy creatures is a barren set of satellites and space locations where you can battle alien nasties, similarly, instead of training at the tooth and nail gym, you will find yourself tweaking your characters genetics with the virtualiser.
I'm not far enough into the game to determine what exactly the differences are between this and crimson moon in gameplay terms. The game does have more player types and to have more missions and quests, but again i'm not %100 sure here.
Either way, Crimson moon had more to it than met the eye, and so if like me scifi is more your than the undead feel free to give this one a try.
Oh and yes, that is my referal link .
Our souls with high music ringing; O men! It must ever be
That we dwell in our dreaming and singing, A little apart from ye. (Arthur O'Shaughnessy 1873.)