Can anyone explain how the 4-3 clip works and if it can be replicated in the Genesis, or any other version?

Just started to run this. I played it when it first came out on the Amiga.

If you stand in this location and jump to the left, it's the first opportunity to enter the door. Don't scroll the screen any more than this!

This shouldn't then spawn the platform below and you can just grab the key and head strait for the boss.

Hope this helps.

Edit: Playing on a Genesis Emulator on a mac.

Dayatee

One thing I did discover on my own was another glitch after beating the final boss.

If you die on the same frame as the game counts down your bonus, an underflow glitch results on your health score. The result being you get over 16 minutes of countdown time and over 6 million points!!

This is my way. Make sure the foot is as close as possible to the crack without 'touching' it. You can make it by using buffered jumps (Hold Jump + Left)