Very interesting! I really enjoyed it. Is every "segment" built by hand? I played until Phase 38 until I started to get bored. But it could be a very nice mobile game.
I love the aesthetic and audio. It really matches the atmosphere you were going for.
I actually didn't mind the ceiling! I started using it to my advantage in order to go down quickly. I don't know if it was intentional, but I didn't mind it.
My main problem is the lack of variety or purpose. After 38 rounds I couldn't make myself play for longer. But it gave me a few very enjoyable moments.
Overall, good job! It's a very nice game and I hope you get to 20 ratings :)