>>713281534
It's fine, but flawed. Mainly just some of the bosses and the soundtrack, which are things Sega could have fixed in a patch or Plus-esque expansion like Mania got, but Superstars never received proper post-launch support because it didn't sell as well as Frontiers in its early release window, an expectation that's still bizarre to me.
Gameplay-wise it plays exactly how a classic 2D Sonic game should (outside some very small issues that most won't even notice), and has some pretty good level design, the latter I was honestly surprised by. The only zone that kind of sucks is the final one.

I've heard the multiplayer aspect is basically broken, but the game plays like it was designed for singleplayer primarily, so whatever.