If you're a fan of cooperative action games like Left 4 Dead and Payday: The Heist, then you may be interested in checking out developer Fatshark's Warhammer: End Times - Vermintide. 

The full game will be free for the next two days to celebrate the game's two-year anniversary. You'll also have until October 26, 2017 to grab Warhammer: End Times - Vermintide for at a discounted 75% off.

If you're unfamiliar with the game, it's essentially the same concept as Left 4 Dead in the fantasy world of Warhammer. Zombies will be replaced by hordes of Skaven, rat-like monsters that come in all shapes and sizes. Fatshark has included an AI system that automatically paces the game so that no two playthroughs are the same.

You'll take control of five available heroes: The Witch Hunter, Bright Wizard, Dwarf Ranger, Waywatcher, and Empire Soldier. Unlike Left 4 Dead and Payday, each unique hero will take on a specific role in the group -- similar to an RPG.

The deal is exclusive to the PC version of the game; you can go to the Steam page and begin downloading it right here. As mentioned above, Warhammer: End Times - Vermintide released nearly two years ago on October 23, 2015, it's available on PS4, Xbox One, and PC.