The perfect Classic Sonic game. Usually, for all the good Sonic games, you can always think of that one level that really gets on your nerves; 2 with Metropolis Zone, Adventure 1 with Big, Generations with Planet Wisp, etc. But I don't think Sonic Mania has a single level or mechanic that makes me frustrated at it.
The only flaw this game really has is that the original levels are heavily overshadowed by the reused old levels, but even then, the reused old levels are so fun to play through. Does it even matter?

Please make Sonic Mania 2, Sega. And I'm not talking about that Superstars shit.