(Edit: Killing Floor 2 is one of the free PSN giveaways for June 2017 and is NOT free-to-play. There is also a promotion running right now where you can save $10 on a year of PSN. It might be a good time to opt-in and nab this game and Life Is Strange for “free.”)
Killing Floor 2 popped up on PSN the other day, so I figured “why not?” I was unfamiliar with the original Killing Floor, but soon found myself looking into that as well. My first impression of Killing Floor 2 was “oh, so this is basically Call of Duty Zombies but as a free-to-play game.” While that initial observation holds true, Killing Floor 2 has a lot to offer for a F2P game. The progression system and achievements keep you coming back for more, while the variety of weapons and beautiful (if nightmarish) graphics are a treat.
THIS GAME IS DARK AND GORY! My new description of the game is somewhere in-between Call of Duty Zombies, Doom, and Left 4 Dead. You have the graphics and monstrous enemies of Doom, weapons and co-op mechanics reminiscent of L4D, and the overall game is a surviving waves of undead enemies a la COD. That said, this game does it well and I do not mean to imply is steals or even liberally borrows from any of those games. While mildly repetitive after playing almost non-stop for a few days, KF2 also has a Zed VS Human mode where you can take on the role of zombie creatures to assist the waves of zombie hordes. While this mode could use some more polish, it does help mix things up.
If you are looking for a fun zombie, survival, or co-op game, Killing Floor 2 is will keep you pleasantly entertained for without costing you a dime.
(see below for PC gamers)