Didn't somebody here want to know if
that unused tune from the PC version of Sonic 3 & Knuckles was Setsumaru's? Well he told me that it wasn't his, and from the sounds of it, it appears it's actually Tatsuyuki Maeda's.
He apparently did all the 2P vs. songs for Sonic 3 (except Endless Mine), and it seems this unused tune was meant to be used for one of the VS. stages, but SEGA decided to use the current Endless Mine song over this.