Completely not knowing this until now, I found SCORPION's Lab. It's not a new level; it's just his logbook. An interesting read, considering it was being written a bit before the events of this hack and throughout the first five worlds of it.
After the Lab logbook, I finish up the Golden Corridors (first tower level). After doing that first tower level, StrikeForcer says that's there's no way to return. I see exactly what he means.
Romhack - antimatterhunter & S.C.O.R.P.I.O.N.
Gameplay - SMCslevelengine
Original SMW - Nintendo
levelengine presently has 668,599 views for Super Mario World across 1,549 videos, accounting for over 28 days of watchable video on his channel. This is 18.25% of the total watchable video for Super Mario World on levelengine's YouTube channel.
4