Now, this is a long shot, and I very, VERY highly doubt this will get added, but the option to create your own level? I know, you can probably mod levels in, but for people who dont know how to mod, like me. I dont really know what else to say.
#Level creator
errant pagoda
main surge
this could also be integrated with steam workshop (idk how other platforms work) just like tmodloader for terraria, which would enable not just new maps, but also new mobs, bosses, chars, weapons, passives, relics and so on