How is the boo sprite messed up? It worked fine on my end. The key and door graphics don't warrant a separate version, but if you guys really don't like them I can easily change it back.
2 player is going to be replaced with a completely separate Luigi mode, I removed it for the time being as a place holder.
The Boo sprite looks off mostly because of the circle spinning Boos, how it alternates from hiding to chasing looks strange with pink face. Nonetheless it is easily hacked back with Lunar Magic etc.
I'd honestly focus on Luigi mode to complete the hack.
I have some simple ideas though to improve it though, perhaps move the old view overworld button (start function) to another button like X?