This demo has a really fun aesthetic that makes me eager to see more from this game. Currently, the level design is a bit basic, although there are a few hints of fun things in Act 1 with how exploration is rewarded. If future level design hones in on this, and takes advantage of the buffed super peel-out in particular, they will be very fun to explore. Act 2 has a hint of less fun things, with the bottomless pit having no indication of danger. Bottomless are fine for more straightforward levels (although they should still be better telegraphed than the one in this demo). However, if this game is meant to encourage experimentation the way Sonic CD does, it is probably better to follow in CD's footsteps in getting rid of them.
I like having both the insta-shield and drop dash, but having them bound to different buttons doesn't feel as good as having them bound to one button like in Sonic Origins. The roll jump lock is also an odd inclusion, it has never been included in a game with a drop dash. Having to use the insta-shield to enable air control doesn't add anything meaningful.
Finally — the OST is really fun! But sound effects are so loud I have to turn the volume down very low, so I don't get to enjoy it as much as I should.