Killing Floor 2

By trapping you and your pals in a large, enclosed area filled with zombies, this shooter is essentially a cross between two popular games, and it works very well. In Killing Floor 2, Europe has been decimated by a zombie outbreak, and it's up to you to survive by using guns, explosives, and melee weapons as their manufacturers intended. Best played with friends, this first-person action game requires teams to work together, as the zombies come at you from multiple directions, swarming players who aren't collaborating. But what will keep you playing is the game's depth. Besides having numerous types of weapons, special skills, playable soldiers, and enemies, the game also has a good variety when it comes to its battle arenas, and it not only has you spilling zombie blood in laboratories and a nice mansion but even in Hell.

Also, if you're more into cooperation than competition, there's a fun mode where teams take turns being the zombies. But while this will capture the attention of zombie-haters with good collaborating skills, it does come up short for those who don't play well with others. Not only is it too tough to go it alone (or even if you just want to play as a duo with your special someone), there's no real story outside the setup to give you a reason to keep going. Also, players will want to adjust the sensitivity of the controls to suit their play style, because the default setting is a bit too loose. Still, if you hate the undead but like working with other people, Killing Floor 2 is a bloody good time.