It's a hack from Japan, by the creator of YPR!

The following is a Google Translated version of the Readme.

Super Metroid YPX
ver1.05 by YP
/////////////////////Change log///////////////////////////
1.05
Terrain and map fixes, and other minor fixes

1.04
Fixed an issue where there was a missile that couldn't be taken in the aisle that fell into the room with the barrier suit.
I'm sorry, there are no missiles in this room.

Bug fixes and other minor fixes

1.03
Bug fixes, some terrain fixes

1.02
Bug fixes

////////////////////////////////////////////////// /////


Thank you for downloading. Patch the Unheadered ROM and play.

----specification----
1. Samus's gravity is getting heavier.
2. I can't bomb jump.
3. Re-rotation jump is possible.
4. If you hit the needle, you will die instantly !!!!!!!!!!!!!!!!!!!!!!!

5. Speed ??booster specification change.
Wall Jump is now possible while maintaining Speed ??Booster.
The input grace is short and it is very difficult, but the game can proceed even if you can not do it.

6. Display in-game time and item percentage on the HUD.
7. The number of items is the same as the original.
8. Other

----difficulty----
If you are playing some hacking, you can clear it.


////////////////////////////////////////////////// ///////////////////////////////////

---- LINK ----
Modified Super Metroid Wiki
https://smethack.f5.si/

Metroid Construction
http://www.metroidconstruction.com/index.php

---- Patches ----
Scyzer_map_fix_saveload
BlackFalconSkippingCeresV2.2
HUD Time and Percent Display