Most companies are cool with modding.. the issue is Nintendo has never been one of them. Modding is very easily inside the realm of violating the copyright of a product. When that product, in this case, violates copyright.. you'd still be doing something with an IP (intellectual property) that you don't own or have a license to. Only Nintendo could give you the right to do so and they'd pull that right away from you in a heartbeat if somehow you could trick them.But what if were not continuing the game were modding it. wouldnt that be consideres adapting ivan work not continuing it.
Edit:
I honestly love the game and I'd be lying if I said that deep down I don't want to see Ivan or someone pick it back up again... that being said it's just not worth the risk. It's a poisoned pill at this point.