To celebrate the E3 release of the Bulls-Eye Content Pack, KILLING FLOOR 2 will be featured on Steam with a Free Weekend and 33% off sale valid from Thursday, June 16th at 10AM PST/1PM EST through Monday, June 20th at 10AM PST/1PM EST.
For those familiar with the franchise, they just released the highly anticipated Sharpshooter perk (complete with a crazy railgun as their tier 4 weapon).
It's a great time to check it out if you have any degree of interest in zombie games.