http://www.jeffsromhack.com/products/d2k.htm Done on WIP MAMEHawk (http://tasvideos.org/forum/t/21778) https://youtu.be/PwUSgdqqDGg
https://tasvideos.org/5325S It's the "Phantom Ladder" glitch. It is used in the second stage of the base game movie, although less visually noticeable there.