Also worth noting is that there's a "theory" (pretty much just a fact that hasn't been officially confirmed) that the arranged PC port tracks were not created for this port, but rather are ripped from an early prototype, earlier than the one archived by Hidden Palace. The main piece of evidence to support this is the fact that Ice Cap Zone Act 2 (as well as Act 1, though it uses Act 2's lead in Origins), Credits, Competition Mode, and the unused theme (which finally gets used in the Blue Spheres mode nearly 30 years later) are virtually identical to the versions from the November 3, 1993 prototype. They also sound much more like they were made on real hardware than the new Super Sonic theme, which sounds more like Jun Senoue's typical pseudo-retro style from games like Sonic 4 and Sonic Superstars.

The last release of Sonic 3 & Knuckles before Sonic Origins was part of Volume 4 of the Sega Genesis and Mega Drive Classics collection on Steam in January 2011:
https://store.steampowered.com/oldnews/4925
https://steamdb.info/app/71162/info/

Not sure what this means by 2011, Sonic 3 did not have a mobile port then and still hasn't to this day.