PLEASE DO NOT GIVE UP ON THIS. There is SO much potential here. I can tell a lot of the jankiness of the game is just something that needs to be ironed out over time - like controls, collision, camera, level design, etc. And it wasn't even that bad. But I have ONE big suggestion.
ADD A ROLL BUTTON!
Is this the Bumper Engine? It feels like it is - and even if it's not, you should still add a roll button. You clearly understand how going down slopes and gaining speed is a big part of Sonic - and thats what I had the most fun with in the level. But it was awkward to initiate this high speed state as I had to stop and spindash in order to get it started. A roll button, preferably mapped to one of the bumpers of the controller, would help this game rise HIGH! A button that sends you into a curled state and keeps you in this state as long as you're moving forward. Keep doing what you're doing here and ironing everything out. There is so much potential here.