This is a nice demo! Very short, but nice. The stage looks absolutely fantastic, I don't know if it's from another game or adapted from something, or if it's original art. If it's original, holy shit, I'd love to see more. The level design is tight, and it plays as well as Sonic Worlds Delta plays, so that's good! I like the title screen, too. The only issue I had were some sound effects not playing, and I had the problem randomly with random sound effects. I've dealt with Sonic Worlds' sound engine, though, so I know it can be a bit of a pain. Keep up the good work!
-Graphics look beautiful
-As usual, the Sonic Worlds Engine does well for providing Sonic-like physics
-I found sound hiccups up the hoo-haa all throughout my few playthroughs. Rings occasionally didn't sound, the peel-out and spin-dash didn't have revving sounds(and in the former case, also had no sound for taking off) and even the springs sometimes completely overwrote other sound effects, up to and including badnik take-downs.
I have to start by saying that the graphics and music really do a good job. I like the rings and how they look like they're a 3d model (probably are), but a very basic thing which is pivot points/hot spots is off, basically, Sonic's sprite animations are not aligned correctly, and this goes for most of them, the idle animation, look up, crouch down.
The ring icon for destroying ring monitors also seemed to have some frames of another item in its Chaotix animation. You also will experience a slow down every time you get an item as well.
But overall it has much potential. It looks really good. Reminded me of Metal Adventure or another name from last year by Blue/Pablo.