Accidentally I found a crash glitch, but I haven't investigated the details yet.
It seems that you have to equip no weapon. (And, you might have to go down with an enemy?)
EDIT (2025/03/20): In this glitch, the game seems to fail to switch banks correctly. This game assumes that the main thread is always loading PRG 14 when a NMI is triggered, but in this movie, the main thread is loading PRG 5 when a NMI is triggered. So, after returning from the NMI, the main thread resumes from PRG 14 instead of PRG 5, and crashes.