Metropolis Zone is a pain in the ass, I play Sonic 2 for years and I'm still getting hitted the same badniks.

Slicer's arms follow the player, making it hard to dodge.

Shellcracker have a horrible hitbox that makes it impossible to not get hurt.

Asteron are a sneaky fuck, it always a gang of these fuckers togethers, they explodes and five spikes fly in five different directions; the worst is when they act like a sniper or when you are using the screws to progress the level and they explode and make you fall the whole thing.

Now think they three together, that's a hell of a zone with 3 long acts. Metropolis Zone is easily one of the worst zones in the Sonic (mainline) games.