So, I've started playing Sonic Mania.
It's...good, but not great. If you liked the 2D games on the Genesis, you'll be right at home here, but this isn't some great leap of quality compared to them. I really struggle to call it better than STH2 or 3, because it relies on these games as a crutch so much. Mainly in regards to the majority of its zones coming from these games, along with the nature of its gameplay. I will say though that these zones are probably the largest out of all the original games. I get the sense that there's more potential paths than ever. I...I'll put it this way. If I was ranking Sonic games on raw quality, Mania would probably be #2. If I ranked them based on how much I actually liked them, it would be much further down. Doesn't help that the blue sphere stages are insanely hard, and the UFO chase stuff is bleh.
Also, there's the question of the plot. Now, you might raise an eyebrow at me even discussing this, but I'm going to go there, the plot is incredibly shoddy. There's enough of it here that you can't ignore the plot, but not nearly enough to make it cohesive. I could go in-depth, but the TL, DR version is that if I was to rank the Genesis games by plot, Mania would be dead last. Because even something as simple as STH1 had clearly defined stakes, and clearly defined environmental progression. Mania can't even get that right. It's clearly a case of "let's throw in these levels at random, and have the flimsiest of excuses to connect them.
Anyway, I'll keep playing it for now.