Sonic/Shadow: Peak level design bogged down by jank. Physics don't play nice with some geometry and some mechanics like the light speed dash are a coin flip as to whether they'll work or not.
Tails/Eggman: The absolute definition of "fine." They're mostly mindless shoot em up stages that're okay at best and inoffensive at worst. Not much to them.
Knuckles/Rouge: Utter dogshit. Radar only tracking one thing at a time makes these stages needlessly tedious, the camera is awful, clinging onto walls is jank, they take forever, and have random jumpscares cuz why not ig. Whoever put these in the game should take a long walk off a short pier.
The story is certainly better than SA1's but that's not saying a lot. It still falls apart like a house of cards under the slightest scrutiny.
In conclusion, better than SA1, still a shit game.

that was like, an actual video game! wow! can only imagine how much fun it would have been to play in the car on a road trip in 1993.
It is not 1993, and now I can take sonic mania on a road trip.
This game has actual level design unlike sonic 2 8 bit, but its levels are extremely short and still not great. The game is piss easy and features "special stages" that're borderline minigames. Even they aren't really that hard; just kinda cryptic. The most challenge you'll get out of it is from the bosses. Other than that it uh, it's a game. It exists.

The screen crunch destroys this game. You move so quickly and enemy placement is so dogshit I genuinely just wish there weren't any enemies at all; the game would be more fun. Bosses start okay but get to be rather bullshit around the halfway mark. The level design itself isn't great because they had to try and accommodate for the screen crunch so, in an attempt to not make the game torture, they made it super automated, except for the parts where it isn't. Funnily enough, the parts where it isn't are the parts that're the least fun, because who would have thought when you can cross the distance of the whole screen in three frames that you wouldn't be able to react to a bottomless pit. Whoops. Skill issue, I guess.