Giving IMR his props in the top left . I must check some of the MK romhacks out again when I get a bit of time - it's a bit of a rabbit hole as there are lots of different version but that whole 2D classic fighting scene and those devs never seem to stop. They've done a hell of a lot of work on nearly all the SNK, MIDWAY and CAPCOM classics released for the Megadrive.
I'm not even sure if this is a hack or something else but the Real Bout Fatal Fury Special homebrew for Megadrive looks amazing - https://youtu.be/DUAPGOBteak?si=x3-G4w1RJpfAQEsP
BTW if you get a bit frustrated burning coasters as you go down this rabbit hole and think about going GDEMU. The BItfunk clones over at AliExpress are going cheap - last time I looked they were selling them for around £30 which is very reasonable given they've been a lot more expensive in the recent past.
And don't sleep on this one courtesy of who else - https://youtu.be/UIWm_tXSq6A?si=s89fIWqG8UX9F8WX