The title screen animation was one of the best touches, personally. I've always had the idea of making one of Hinote, but this takes the cake and runs with it.
I gave this a play, and right next to Hinote, it's easily one of the highest quality characters made for this game, MotorRoach. Most custom characters have at least one glaring flaw somewhere, (Especially with all of my old characters.) but I saw nothing of the sort here.
The animations inspired by S3&K add further character and uniqueness to this Knuckles. I have nothing but praise for it, the coloring is very crisp and consistent with the game's art style. Well done, MotorRoach, and I too hope this makes it into the vanilla game. This is more than a better Knuckles skin, it's Knuckles as we know him.