I think it could be nice, that the turtles have their own individual categories, to see them in action.

This idea sounds really cool. To have variety in the game.

Hey.

No.

Unlike in TMNT3/1 there's no real advantage to using the other turtles. We could definitely bring it up again, but talking with everyone about it in the past, there's literally no point as there's no difference / challenge between using Leonardo, Donatello or Michaelangelo. All 3 turtles (-Raphael) share the exact same hitboxes and have no unique special attacks that make them different. Adding turtle specific categories would be purely cosmetic and just serve bloat the amount of categories available (and this game already doesn't have many runners to begin with).

I think it's the most unpopular of the 3 games on NES.