To play the linked movie, you will need to poke RAM addresses FC5A and FC5C to values of 3 and 6, respectively, to start as Iron Knight on Highwater Pass 2.
This insane glitch was discovered by Favini01 a couple months ago. Not only does this instance of it save time in a full-game speedrun setting, it is also completely viable in real-time! Here's the link to Favini's original video:
https://www.youtube.com/watch?v=1aZVvzDBDAY
In some places in the game, standing on a certain pixel just left of the level margin (6 pixels in this case), will for some reason trigger the telepad below Kid which is nearest in Y position. There are two telepads in this level, and the one leading to Elsewhere 1 is both below Kid and higher in Y position than the other one, so the Elsewhere 1 telepad gets selected here, and the result is we skip most of this level! What happens if there are no telepads below you in the level? Interestingly, the level will restart you with the stats you had when beginning that level attempt; transformation, life count, diamond count, and all.
Now, Favini found that the glitch can be used in this level but would require at least 3 HP to pull off because the out of bounds here damages you twice before you can teleport. That would make it impossible for Kid to perform the glitch by himself. But this video demonstrates that you can use invulnerability frames after losing a helmet to protect you for some time while out of bounds, effectively making it possible to pull off as Kid. This was something I'm not sure Favini realized when posting his original video, so I wanted to make sure this was known.
This out-of-bounds teleportation thing is mostly only possible in TAS, as it requires airwalking into the margin which is not human-viable. Now, what makes this glitch save time and be viable in real time for this level in particular, is that you can very quickly and consistently get an enemy to lose your helmet while ducking and touching the margin of the level. When this happens, simply hold down-left during the de-transformation animation and you will crawl out-of-bounds!
Hold down-left until the screen starts to rapidly scroll to the right. When this happens, you have 15 frames to transition directly from holding down-left to just left. Hold that left input for exactly 8 frames, and then let go of everything. If you did all of that correctly, the game will start to lag a bit before you are eventually teleported to Elsewhere 1! Here's what'll happen depending on what you did wrong:
–If you start holding left too early or hold left for less than 8 frames, the glitch will not be performed successfully, but you can hold right to escape out-of-bounds.
–If you waited longer than 15 frames to transition from holding down-left to left, you will run out of invulnerability frames and die before the teleport could happen.
–If you hold left for longer than 8 frames, you will hear the sound of shooter blocks activating, blocks breaking, and eventually the game will crash!
This skip could realistically save like 8 seconds if pulled off in a real-time, full-game speedrun setting. While the opportunity to perform the skip comes up only 2 minutes into the run, the precise timing of having to hold left for EXACTLY 8 frames may mean lots of resets if you're not consistent at that sort of thing. I'll be curious to see how long it takes for this to be picked up by runners.