One thing to consider is an end goal for the player. That way it will give you a definitive end point as well so you don't spend too much time defining the special resources and monsters (feature bloat can unfortunately bog a project down). If the procedural generation takes too long, you can still hand craft a level or two to show off the rest of the mechanics. I'm interested in seeing what these special resources are and how the player will use them!
Yea for sure, my plan is to put a boss at the end of the cave that the player has to fight with the resources/stuff they gather during their run throughout the cave.
If there was more time, I'd like to add persistent rewards between runs for the resources gathered during each run. But that won't be feasible to do during the jam I think.