That was a fun challenge! I like the atmosphere of the art; it's very lonely and foreboding.
The "look up and down" mechanic was helpful. Although, the "look up and down" viewport doesn't move when the character changes screens.
While most of the game was a fair challenge, the hardest part of the game was climbing up the long shaft after unlocking the wall jump. Repeating the small wall jumps is surprisingly difficult; there's very little margin for error, especially with having to change movement direction with every jump very quickly.
I don't think I could recreate it, but I encountered a funny bug where I cleared this specific section by dashing while falling into the ground, causing my dead body to slide into the checkpoint.
All-in-all, great work!