I know it's silly to get hung up on flavor, but how are dungeons tied back to the idea that a duel is 2 cranky planeswalkers hashing out a disagreement.
are you and your opponent fighting while *IN* the dungeon? that allows your venture critters to attack the opponent while still moving the dungeon forward. But if that's the case, there is a missed opportunity for dungeon rooms to impose some symmetrical statuses similar to enchantments. EDIT: I guess tomb of annihilation fits this bill, but where are the "all players create a 0/1" or "until the start of your next turn, all players have 1 extra mana of your choice in their pool" or something symmetrically positive?
If you and the opponent are NOT *in* the dungeon, then how is your venture critter attacking face while still getting deeper in the dungeon? just teleporting in/out of the dungeon at will? why not just teleport to the treasure chamber or any room you wish then?