For a long time in my childhood and even into my adulthood, I completely did not realize Sonic CD was really a thing. I imagine I had at some point seen or heard about it, but my affection for the Genesis was never so great as to spend that kind of money on a wasted peripheral. So I just put it into the back of my mind and never considered it. Sonic to me, like many franchises, was swallowed up in the 3D era and forgotten about. Which is to say I pretty uniformly hated each and every transitional game of 2D into 3D. Yes, even that one, or that other one you're excited about. Yes, Sonic CD is 2D and gorgeous 2D at that, but by the time I had the funds to pursue a Sega CD, I certainly wasn't interested in doing so.
I
believe the game was ported to be PC a long time ago, but I never saw that either. I hadn't realized I could be playing the game until it was ported to Steam, and even then, I think I pirated it and played it briefly before forgetting about it.
Sonic CD has, to my understanding, an interesting history. It is a marquee title for a system that sold very few copies. It is basically like headlining the titanic. It is also the product of splitting the Sonic team in half and producing two Sonic games at once, with rapidly divergent design perspectives. I feel that itching in the back of my teeth when I read about it, that sensation that the whole story isn't being properly presented to me, so I'll let readers do their own digging. It's certainly an interesting way to continue a franchise.

Sonic CD on Steam is, to my understanding, the Taxman / Christian Whitehead port in all its glory, and it does run well. There's a story about that guy in the first half of this Superbunny Hop video
here, which deals with Sonic Mania, the announcement of which feels oddly coincidental. I didn't know, but realizing I picked up the anniversary bundle and this is the 25th anniversary announcement, it actually isn't much of a coincidence.
This is Sonic game #3 (done in chronological order) of Summer of Sonic. The previous game is
here, and the next game will be
here, once I actually get that written up.