A Dungeon-Crawler Where Your Friends Control the Monsters. Something like a Retro-Arcade PvP Bullet-Hell Dungeon-Crawling Roguelike-lite-alike?
It's one of the greatest local multiplayer experiences I've had. It's one of those games that is incredibly frustrating in a good way.
Not sure about playing it alone, but with friends it is horrifyingly fun and really fleshed out.
Presentation is incredible, and there's a lot to unlock. I'm addicted.