There is no trick for that.
As I wrote here, I'm not sure if level 12(a) of Mysterious Castle can even be finished.
Aram wrote it can, but I wouldn't know how.
This is not a very exact description of how to perform the trick...
Yes..the trick is fall in specific place over tile (can fall over wall, chomper n dont die,or over the guard..in the video speedrun..you can stop ,n press up or run n press back or run n press down,but rememnber" the distance"press in specific moment ...in level 6 ( Jaffar Revenge),if you want take lp,you need fall over fat guard..if you change fat guard for wall..you can move fast..like the speedrun
I know, friend