I'm only going to comment on the visuals, because they are beyond gorgeous. Your writing is engaging, I think you can tell a good story, and craft a world to hold it.
But really, the visuals.. Man, I've always been a fan of that type of geometry and texturing, some of my all time favorites have used that to great success, it's timeless and super effective. The way you introduced modern PBR techniques into it without reducing the "retro" aesthetic a single bit, you just managed to make it that much better.
No exaggerated shadows and light/dark points on normal maps like you so often see in high contrast flashlight games like this. Everything is just tasteful and an easy 5/5 on the artistic score.
I'd love for you to maybe introduce proper physics into it as another modern addition, with the right tweaking on rigid bodies nowadays (and the simple geometry) you can do stuff in your level design they could only dream of back when this style was necessary.