Rocket League

Rocket League is the quintessential party game of the generation. Taking the concept of having a random kick about with your mates and propelling it to a Sci-Fi remote-controlled motorised bonanza is, by all means, almost bat sh*t crazy. But it works, and it's easy to see why.
The game's main feature is of course entirely focused on an online component, pitting teams against each other with the objective of yep, you guessed it, scoring as many goals as possible. It requires a really important level of teamwork however, as players have to coordinate a strong defence, midfield, and attack in order to successfully dominate the pitch. At the end of the day all you're really doing is hurling a toy car at a giant ball, but still, there is an element of cooperation to it.
Psyonix's decision to release the game free to all Playstation Plus members was a corporate masterstroke too. The subsequent buzz generated from its initial mass uptake has led to the title being downloaded millions of times, easily blasting the studio's original car-themed footie experience into orbit.
Of course, this won't be the last we've seen of Rocket League. It's now a downloadable phenomenon, resting in the libraries of countless gamers on PS4, PC, and Xbox. If sales figures alone are anything to go by, there's little doubt that Psyonix will be taking full advantage of their fledgling brand's popularity in the coming months.