It's like two games in one
The Mighty Quest for Epic Loot is an upcoming title from Ubisoft that sees you raiding castles and dungeons. That's only one part of the game though, as you can build your own custom stages and then have your friends try to clear them.
This seemingly came out of nowhere and the crazy thing is that you can go try it out right now for yourselves in the beta. And even crazier is that this looks like a load of fun. I have yet to give it a spin, but let us know what you think of it in the comments.