Here's what I am working on but I'm not sure where to take it next. I am keen to hear ideas. I would like to make it rogue-ish (no saving, start from zero every game), and use procedurally generated levels. But aside from that I am open to thoughts.

I think I would add a kind of bank-and-relax cutscreens, Like "okay, you've gathered 6 jewels so far, but unless you put them into the lift bin, that's not helping anyone". You could also put yourself into the lift bin, leaving all you gathered in the mine (and not banked earlier)

Looks awesome! Super cute sprites. :) Is the tempo by choice or are you nearing a processor limit? I'm not really a rougelike-fan myself, but I do enjoy procedural elements.

I like how it looks so far! I might be interested in featuring this, when you're done with it, in an issue of Loadstar, our revived version of the clssic C64 disk magazine. We would pay you a bit to publish it, but we would _not_ be looking for exclusive rights.