Incredibly cute, super hot, very well done! I will definitely become a Patreon when I have the money!
My only suggestion would be the addition of more customization for her body type & the add-ons. I'd love to be able to change her height & breast/butt size, along with being able to have a demon tail to go with the demon horns.
Other ideas I'd literally pay to see:
A few more positions & a side menu to access them.
Ability to pull panties aside instead of taking them off.
A "futa" option in the add-on/customization menu.
Being able to smack her butt along with rubbing it.
A detailed anus with a gaping animation when the player turns the cock visibility off.
And if you ever make one about a guy, I'd buy that, too!