Got to the end of the demo and I'm loving it this far!
I'd just like to say that I think the mechanics are really unique, and I think it adds a lot to the game - in particular, switching between the different "modes" with the number keys. It's very interesting and I'd love to see how it gets used in further updates and areas of the game! [EDIT] I totally didn't know the Soundtrack was already available for purchase. I'm definitely buying it right away!
I think if I had any area of complaint, it would be that maybe there are a few too many dead-end paths, or too much empty space? Of course, you could be waiting to fill up these spaces with secrets and such, but for now it's just a little tedious to someone like me, who likes to thoroughly explore the world. The best example I can think of is in the snowy dream forest where the VHS tape is found, there are one or two "looping" paths that don't really lead to anything significant - they just go around some trees and back to the main area. It's not a significant issue, but I thought it would be worth mentioning.
Overall I had a great experience with this demo, and I'm stoked to see more! I'll definitely be recommending it to my friends