You have something special on you hands, man. That Intro alone had me SEATED, and then seeing the 3D RPGMAKER ASSETTS was a moment that had me floored. Visually, you knocked it out of the park in almost every area. Only thing I'd say stuck out to me was the Blur/grain. For the most part, the grain was fine and served its purpose to add to the mood. Other times, especially in the VHS sections, there was so much blur that I had NO clue where I was going and what I could interact with. It doesn't help that the movement is a tad clunky at times, but eventually I got a hang of it. The VHS sections themselves are sorta the star of the show, as the little scraps of narrative are trickled to the player through them, and I'd be lying if I said i wasn't interested to see what the whole substance and dream bits mean! One thing that stuck out to me that I love is how you wear your influences on your sleeve. Dr. Ito, Dr Sunderland, The opening mirroring SH2's pretty exactly, the substance... THE DOG ENDING... I can tell you had fun with the ideas you had kicking around. Good artists borrow, Great artists steal and all that. One thing I'd love to see in the full version is more puzzle elements tied to the VHS segments. As it stands, the VHS segments serve to just give you a key that wasn't there before most of the time which is cool in its own right, but is only the beginning of what crazy stuff you can do with the concept.
All in all, this is a great proof of concept with a lot of fun ideas that I can't wait to see more of! Great work dude!