8. Warframe
Playable for free on both the PC and PlayStation 4, Warframe is a cooperative third-person shooter in which four players team up to work together on a randomly generated mission, eliminating enemies or capturing data from mission terminals. You level up as you shoot your way through each cooperative mission, and earn rewards to deck your character out with new abilities, weapons, and gear. Paying for items in the game is just an added way to distinguish yourself from the rest of your team.
