Sonic 1 poses the question on how to best design a high-speed 2D platformer. Green Hill Zone is the answer.

this game blows man. stiff controls, game design that doesnt take advantage of the strengths of sonic's gameplay, platforming was so much of an afterthought that it's entirely comprised of floating platforms with terrible pop-in, it feels like the people who designed this have never played a sonic game before. i don't think they could've made a lamer open world sonic game if they tried. at least the super sonic fights were cool i guess