Contact. Unfortunately, it's in German so probably not very useful to you.
It's basically a pen-and-paper adaption of the old MS-DOS XCOM games with a d100-based Shadowrun-esque combat system, a stat/skill system that feels like Fallout 1/2's SPECIAL, and an experience system that feels like Morrowind's. It's well-written, most of the rules are sensible, the world is fun, some of the aliens are very creative, and the artworks are great.
Despite being well-received, it never made it out of Germany. Right as they were gearing up to launch the English version, the publisher suddenly went bankrupt and the bankruptcy manager forced them to to cancel all games except the biggest one. And that was it for a really fun game that wasn't even done picking up steam yet.