This is a prototype of a Sega CD tech demo, created by Sega Multimedia Studio. This was later shown off at SCES 1992, and often confused for being a CD version of the upcoming "Sonic 2". This pre-dates the version Hidden Palace dumped by a little under 3 weeks.

Hey, wait a minute! Why does it play the music from Sonic 2's unused night club scene at 2:50?!

YouTube upload here:

its that goofy ass music that didn't make it into sonic 2 at like 2:47

glad this bit was still in here

Where did this come from?

upcoming lot I'm involved with. more will be revealed within the week

OK.

There was at least early dev ideas for a Sonic 2 CD right? Then it bssically became Sonic CD instead. But yes I remember stills from this demo being promoted as "first screenshots" of a Sonic Mega CD title.

As far as I'm aware, there were no plans for a Sonic 2 CD. Sonic CD itself initially started as a version of Sonic 1 for the Sega CD, before it became warped into its own remixed version of Sonic 1.

Ah I guess I assumed the early TT concept for 2 was intended for CD format. It seemed a bit bold for cartridge. Its kind of interesting that CD would end up adopting the scrapped concept for 2 though.

So cool to see! I remember the still of Sonic holding the CD in magazines way back.

This did more than the ps5 and ps6

"prototype of a tech demo"

you'll be surprised the insane kinds of things like that that's been found. there was once a prototype inside of a prototype

how did you even obtain this anyway? was it just through connections or did you find it elsewhere?

Eggman Literally Messes with Sonic when he just Spins The Disc

Wow, this is amazing!

Oh wow, this predicted Sonic going to San Francisco