Chemical Plant Zone
After beating up the Death Egg Robot and witnessing again the power of the Phantom Ruby, Sonic finds himself in the second zone of the game, Chemical Plant. Returning from Sonic 2, it's the same as it was there: Westside Island's very own flooded factory, because what kind of island would be complete without that?
Just like Green Hill, most of the Badniks here also originate from this zone's original appearance, but those guys having nothing on the infamous sea of purple-pink chemicals that fill the factory (side note, i just found out while researching for this that the liquid is officially called "Mega Mack" according to the American Sonic 2 manual, which is pretty funny), which is, of course, responsible for a lot of frustration among those who don't know the shortcuts to get around it. Some things never change, I guess.