u/desperatewatcher

My dad used to play this game back when he worked for this one company.

It was VERY fallout in building style and decor but much much darker. You had a lot of grenades and guns and involved going on missions in a fairly open world fighting aliens and maybe zombies. Very violent for the time with lots of blood and gore. I remember playing it while he had meetings and finding it pretty hard. It was NOT turn based.

EDIT: Looks similar to but darker than Alien shooter, and less FOV. You could also see the outsides of buildings as you worked your way through destroyed settlements. I also checked with my mom and apparently my dad left that job in 2001.