Just try to beat every dungeon in the game! And if you want you can do co-op with friends or online to beat technical and special dungeons. They just recently added The story dungeon so we got to wait for more. Once you finish the Normal & Technical dungeons, the special dungeons update all the time. I guess sometimes they add crazy dungeons on the technical, but not too often. If you want to progress in the game, rank up to the point you have enough stamina to enter dungeons with 99 stamina.