Oh my god. What a pleasant surprise!
It's rare to see such a casual mastery of vertex slopes in a stage like this. Honestly this is incredibly impressive. You've successfully captured the Classic Sonic feel with this, and it's super replayable and fun to route.
A few points of criticism:
-I think some of your geometry and your slope usage is a bit overtly jagged, it can lead to you flying places you don't want to go, or grassy terrain feeling a bit too fractured
-That final spiral at the end is super long and slow even with momentum mods.
-Some of the texturing is super jank, even in OpenGL
Amazing job! I hope you continue to make levels in the future
Thanks a bunch for playing! I'd like to make more as soon as possible!