I'll start with my complaints/problems with the game:
-Selecting to start with a penis doesn't actually give you a penis.
-Choosing oviposition for the tentacle lair is suboptimal since your recruits only reproduce tentacles once. This wouldn't be so bad if you could continue to recruit volunteers, but you only get two opportunities to do so. Selecting to impregnate human girls gives you infinite tentacles since they continually spawn tentacles and never leave.
-after getting the forced orgasm school upgrade it's better for you to immediately fail the director's office minigame since she'll most likely get molested by tentacles.
As for ideas on what to add, I have one real suggestion
-I never use 'Dreams from the worlds of pleasure'. Seems more effective to just summon more tentacles to molest you since it gives you orgasms along with increasing corruption. You could maybe unlock new upgrades or transformations that are more exotic like making you have your own tentacles or other inhuman traits. Maybe have it act as a temporary discount for other spells since you're more attuned with the tentacle realm? I think it should just do more than increase corruption.