I have no idea if this has been suggested before or if its even a already planned feature but I think it would be cool to have challenges you can active in the town for Arcade Mode there was that one quest from Bishop that you had to get to Floor 3 without gaining any xp and fighting all elite mobs but I was wanting to do a no xp run with normal mobs or a xp on elite mob only run. I'm sure others could add on to this with challenges they think could work but while I was doing that quest all I could think of was those two.