Whatever they can comfortably fit in without having to dump weeks of work into it. Easiest would be colors, but then there's things like picking the character's gender, adjusting different sizes, species, boob size and so on.
I could attempt something like that, but as it stands the whole character alone is 9 sprites, each to be edited for skins/customization. I think I'd like them to stay a bunny, but i could do gender stuff
