Thanks a lot!
I can see your point about the dungeon selection. I kept it because I liked giving the player the option to go back to an earlier dungeon if they wanted to, and the next dungeon is already selected automatically, so continuing only takes a moment.
That said, you're right that in the current version there isn't really a strategic reason to go backwards, so the choice doesn't add much mechanically. Definitely something I'd reconsider if I expanded the game.