I'll try and do it again to see wtf is going on but I'm guessing it only works because of the door closing. If we can somehow get to the bottom loading zone of every level with some weird tricky movement then the whole any% run is dead.

When this becomes confirmed by Fin and Kohlmannm (I could be lying and faked it, but I swear to God it's real), then will it be allowed in Any% NLS? No Level Skip already literally skips a level anyway (but allowed because it's not using the level skip glitch, like this).

I still don't know how this works, but I put a link in resources to a modded version of the game to test this easier.

I have observed that on the very first frame of fadeout, the cat ninja is not rolling. When fading into the next level, it is rolling down right (down right not due to momentum, because I scrape the wall on the right for a little bit). It is possible this has nothing to do with it though.