Alien Swarm

Originally Posted : December 18th, 2010 @ 4:03pm

Challenging at the higher difficulties and requires good team work in order to progress. But with only one short official campaign it's only fun for awhile.
There are different equipment combinations, player characters, and corresponding skills. Coordinating those with your team is often vital to success at higher difficulties, but when in doubt, flamethrower always works.

TL;DR : It's free, it's fun, it's short, definitely try it out. With friends if you can too.