I played the demo about 2 days ago and I thought it was OK.
But definately, there is some issues that are weird, because you know, the small chubby Sonic really feels heavy.
At one point, I agree with the visuals, it took a while for me to adjust, the colors are way too saturated and it shows.
Nevertheless, I am looking foward to this.
Because despite these minor quips, the game looks pretty much flawless.