Have some class
A Dungeon Game deliberately doesn't have any classes because absolutely fuck writing that stuff, but also I started playing RPGs with AD&D 2e and I'm really a trad player at heart. So of course I'm now sitting here thinking "what if I wrote some optional classes though?"
Thankfully I don't know what I'd do so it's not going to happen any time soon (because if I did have ideas I'd probably work on this to the exclusion of everything else for the next week) but it's potentially worth thinking about. It might mean tweaking what already exists to make running with no class still desirable (e.g. I'm already wondering about my XP thresholds and whether they're too high so possibly I'd lower them for vanilla a little and have the higher thresholds for characters with a class).
Just idle thoughts at the moment though. We'll see where they lead.