Decided to get a free hat download Alien Swarm, and it looks somewhat interesting for a top down shooter. I'll get my free hat play and come back to edit this post to evangelize the glory of hats game.
Edit: It kicked my ass repeatedly, as fitting for a game inspired by Alien. It was fun when I was wasn't getting ripped to shreds and most likely getting my face filled with embryos by means of a long phallic pharyngeal mouth.