This feels like one of those experimental isometric platformers from the 80s, in both a good and bad way. The art and soundtrack is great; there is a lot of creepy foreboding atmosphere!
The mechanics are unfortunately quite bad. It's almost impossible to tell where you are while in the middle of a jump. It's very easy to fall off of platforms. The hitboxes for enemies are weirdly large. Collisions for hallways are strange. Various bugs. I couldn't finish because I got stuck on the other side of a warp and got stuck in an endless loop of death.
It's not unsalvageable or anything; all of it can be ironed out. For one, I would try focusing the camera on where the player's "ground level" is, instead of where the player is in the air. It might make jumps less confusing.
The audio is a tad loud, especially when sound effects start stacking on top of each other.
All things considered, good attempt! Congratulations on the submission!