is completely FREE to download and play on Steam. It's designed with co-op in mind (although there is a offline single player practice mode) with up to four people playing.
For those of you who get motion sickness when playing FPS, you'll be happy to note that Alien Swarm
is NOT a first-person game. It's actually played from an isometric viewpoint, so you can see your character and your teammates easily.
If you have already have Steam -- and quite a few of you do -- I'd strongly suggest downloading this game. It's fun and although extremely light on story, it's a great game to play alongside a group of people.
In fact, if some of you were willing, we could play together. I think it'd be fun if we could get a group together.