Sonic 1 has a strange level order and confused design dropping it's main selling point of speed based platforming for precision based platforming almost immediately after Green Hill Zone and not really revisiting it outside of maybe Starlight Zone, and the difficulty whips between easier stages like Green Hill and Spring Yard and harder stages like Marble and Labyrinth. Despite it's odd pacing it's still a great platformer, and while the controls and momentum aren't as polished as later games it still stands out above most of it's peers from the time that aren't about middle-age plumbers.