All the art needs to be re made. If you have time and energy to take this task then you can try :3
The game has 37 finished breeding animations but those could not be used if the game would be re made. So I just quickly counted about 2070 breeding animations would need to be done (not counting the extra monsters what don't have designs yet like genderbend mandrake and others like that, counting those too it would be even more).
Also cause all the art should be done it also means that the idle animations should be done, backgrounds, items, text boxes, different hairstyles, different faces, all characters, extra character animations, seasonal minigames art and so on. That is ALOT of work and I would not want to do new art for the whole game. I would gladly just do the missing animations but that's not possible to do.
It's actually much easier to make totally new game than trying to re make everything.
I have been planning of making my own a simple breeding game but I just need to get time to do it. At the moment I'm doing two jobs just to pay the bills so the game idea needs to wait