Killing Floor available for free on the Humble Store

Killing Floor, one of the better zombie shooters as of late, is currently available for free on the Humble Store. Humble also have their own sale going on and while it isn't as extensive as Steam's, there's still some deals to get your mitts on.

What's even better is that when you download it, you get a few three-day guest passes for the game that you can hand out to friends. Who's down for some zombie slaying action?

It's available for just over another day, so check out the Killing Floor trailer below.