There was a demo for this a few months ago. It wasn’t very good. It was “classic” Sonic in a re-imagined Green Hill Zone, ruined by awful physics, jerky scrolling and not being able to see anything as the graphics were too “busy”. Oh, and Sonic was about one tenth the size he should have been in relation to all the other objects and baddies.
This demo improves on the previous one greatly, by fixing much was wrong with the physics (although they’re still not correct), and then makes it over fourteen billion times worse by not fixing anything else, and adding speaking Chaos who you can’t kill, feed into a mincer, or set on fire, and being quite frankly, insulting.
Then it added a “modern” Sonic Green Hill Zone level, which, like most “modern” Sonic games was a test of how long you could hold the same direction for whilst sometimes pressing a button to jump, duck, or activate the real-life Childhood Memory Eraser. The latter of which sadly doesn’t exist. Instead, grinding rails, having no control over Sonic for large portions of the level, and being unable to see what is coming in those sections where you do have some control, all combine to form the greatest Sonic gaming experience since, oooh, Sonic The Hedgehog: Stabby Eyeball Adventure.