If you like casual multiplayer party games like Towerfall give
Knight Squad a try, it's an absolute blast and well worth the $10 Steam Early Access. I've been having a lot of fun with this game.
Here's the quick description from Steam:
Knight Squad is a 1 to 8 players game that can be described as SNES era Bomberman meets Gauntlet. Play as a Knight in the arena and defeat your opponents using epic weapons and power ups.
There's no online multiplayer yet but the local co-op alone is worth the early access imho as there's a variety of game types including standards like Team Deathmatch, Capture the Flag and Last Man Standing as well as some unique ones like Domination, Gladiator, Crystal Rush, Grail and Soccer that work really well. Multiplayer is the best though it's still enjoyable with all computer opponents, the AI bots are no slouch. Easy to learn and addictive to play.
I'd recommend it if you like this type of game and especially if you have a few friends you want to beat up on.