Played the demo last night and just wanted to leave some comments:
1) Assuming this is supposed to be the first stage, you might want to not include so much water. If you're trying to grip someone to play the game then you'll probably want more high speed action instead of slow underwater segments
2) The pose Sonic pulls when he launches off a spring looks a bit unnatural. Might want to straighten him out a bit
Other than that it was good! Graphics were nice, really liked the Sonic sprite and it played as good as a Sonic Worlds-powered game should. The only thing you might want to think about are some original gimmicks that'll help make the game stand out a bit more.
Otherwise a good effort