Nothing, Nintendo can wipe it at any moment. The dev will probably not get sued if he removes the game at the first request and since he hasn’t monetized it in any way. But if Nintendo feels like it he can definitely get sued.
We can hope Nintendo let it be, but in the past they’ve killed many fangames like this one. Like the 2D OOT which was very good but got wiped by Nintendo.
My computer is like “Kernel panic” and I’m like “Same man, same…”