Really good demo! It's great to see Overture come back after many years. It looks good, and feels good to play.
I'm sure that others may have brought this up, but I did notice a few bugs and quirks.
The wrecking ball in Granite Zone does not contribute to Link chains, The spinning fireballs in Granite Zone Act 2 only seems to have collision sometimes, the title card for Granite Zone Act 2 is incorrect, some slope collisions cause extreme acceleration which is a little jarring but still feels good either way.
The new music for Sunrise Gate isn't bad by any means, but the original soundtrack by Great Lange is a large part of what made the original Demo so iconic for many people, including myself. I have a lot of nostalgia for them. If possible, I'd love to see his tracks incorporated into this game in some way. I did try to reach out to him quite a while ago to see if he had any lossless FLACs of those Sunrise Gate tracks, it seems he may not be easy to get ahold of.
That second boss fight was great by the way.