Very interesting concept. I loved the aesthetic of the game, especially the theatre area near the beginning. I also thought the power plant area was unique. I would've liked to see more of the surreal environmental design, as I thought the castle near the end was less interesting, and furthermore, became disorienting since screens/locations therein seem to not connect in a plausible way.
What I loved: The puzzles were great! Just hard enough to make you think but not too tough that you ever want to give up or look up a guide. The age puzzle and the statues puzzle reminded me of Silent Hill puzzles, which I think is a good thing. I also very much enjoyed the music, especially the droning track that played during the title-screen and that was interspersed a few times throughout the game. Very eerie! I also enjoyed the monster designs. Simple, but effective.
What I didn't like: The camera was often too far away to see where exactly my character was and where I'd have to turn. I understand the tank-controls are for nostalgia's sake, and I actually don't mind them. However, if we have old-school controls, it shouldn't be made even harder by not being able to see where I need to turn. This is especially problematic when being chased by an enemy. Secondly, I didn't like how your character could wander off screen, out of view, before the game would switch to a new view. As soon as the player wanders off one screen, ideally the game would immediately switch to a new view, where the player character is immediately visible again. To have the player be in a "limbo" of two camera angles can be disorienting.
All in all, a great concept. I'm excited to see where it goes from here!