SWOOOORDS! Colon Lords of the Sword is a 4-player cooperative dungeon crawling action game made in Unity 3D, inspired by Gauntlet, Golden Axe, Bastion, and Spiral Knights.
A really great game to play with friend!
(Just make sure you all have a controller each!)
But the gameplay itself can give hours of repeated play, especially since the depths randomly generate the level each time!
Worth a shot especially since its free!