What is the demon that appears in stage 2 that Nesche tries to escape. The floating purple demon which craves women and rapes Nesche? Have you put lore about the demon into the game somewhere where we can read about it?
Having that as the last boss sounds exciting. If there isn't lore yet, no problem. Perhaps you can ask your Patreon members to pitch ideas. Speaking of Patreon, how can we contribute to the game's development? You mentioned people will get mentioned in the credits in one of your posts. I think you said it. If I'm wrong, ignore me.