Fun with Friends: Pitfall Planet
What a great couple of years it's been for the concept of playing games together in the same room! Pitfall Planet is a game where you and one other person play as little robots shipwrecked on a planet full of platforming puzzles that require you to throw and grapple each other across gaps and past obstacles and enemies, and then you buy hats with your hard-earned loot.
It's not the best cooperative game I played this year, or the best game to feature robots wearing hats, but it has all the qualities of a successful cooperative game--the mechanics are simple to learn and execute, success depends on teamwork and communication, and failure is hilarious.
In fact, I'm not sure I laughed more or harder at any game on this list than I did at Nina's and my futile attempts to steer Pitfall Planet's car around the map. A feature that would have been maddening in a single player game became comic brilliance when playing with a friend.