I got idea how to make lust doll plus sized
Unfortunately, body changes like fat or muscles isn't really feasible as all the graphics for clothes in the game would need to be changed for them. I'm considering the possibility for this sort of thing in a potential sequel.
You may want to look at vector graphics, I don’t have any libraries at the top of my head, but it’s likely what I’ll be using for my game.
Edit: libraries as in ways to interact with the svgs, kind of like trials in tainted space.