Frankly. I didn't decide it yet) Originally, the main goal was kill the GOF. But for now, I want to expand story.
Ah ok. I find it easier to give proper feedback when I know where the story is supposed to be headed.
My personal wish for the overarching story would be that the player gets to decide how lewd he wants to be and a bar that tracks the players lewdness, that then influences parts of the game. For example, in Letel's dimension, you have the choice to embrace all the lewd things or not. If you do, that cute succubus that spawns when the player reads the book might just decide to keep the player. If you don't Letel could be weakened.
Some NPCs might only be interested in you if you had next to no sex, others if you had a lot.
Specifically, I'd love to be able to tell that succubus in Letel's dimension to grow a penis and take the barbarian all night. If she does, the succubus will spawn in hell and you can 'recruit' her for your cause, for a price of course. Or the barbarian could succumb to the succubus and join her ranks.
As for smaller fixes, I'd like to be able to just surrender to enemies. Also, in Letel's dimension, you can close the door to the bedroom before sleeping, but the bed event doesn't take that possibility into account and plays out like the door was open.