also maybe a debug menu or stat menu? Im not too savvy on how to create those in HTML so take it with a grain of salt lol.
Those are all solid ideas. As you said, this style of game could very easily get out of hand in terms of its scope. As such, as I try to plot out the game, I think I'm going to need to establish a priority list.
My thoughts:
1. There will definitely be a gender-swap option at some point going forward. It's a common enough theme in expansion and MC works that it'd be worthwhile to do.
2. Mythological stuff would be kinda interesting. I could see that as some late-game content; having a holstaur, goo girl, or lamia as part of the cast would be fun. I would need to establish a better base for the game going forward, though, since at the moment I'm doing some revisions of my initial plan.
3. Body-part-swapping or body-swapping could be fun, but depending on the format of the game, it'd be rather hard to do in Twine. Harlowe isn't an object-oriented programming language, from what I understand, so it'd require a bunch of additional variable-juggling. If I were to make the switch to a Python-based system or something similar, I could conceivably do it, but that's a distant goal.
4. I'm gonna be honest, I'm generally into people getting bigger rather than smaller. SPH is gonna be a low priority. Body shrinkage (ie, minigirl/miniguy) is still possible, but I'll need to get a better workflow going for that.
Debug menu is an absolute must, I agree, particularly from a developer-side view of matters. I'll look into how I could set that up in Twine.
I was using the "think about your wife/life/relationship" as a sort of narrative stat menu, but A: I'm kinda struggling making that sidebar mobile-responsive, and B: I do think that having a number-based page would improve matters as well. I'll look into those.