Wow, you've absolutely nailed the creepy atmosphere, the character sprites in particular are fantastic and really well animated. The music, visuals and enemies work really well together (even if I did have to turn up my brightness!). I also love the text within the level giving you hints, and the swinging poles add a good amount of challenge.
Usually floaty controls are a negative for a platformer but I think it works well for this style of game. I did feel that the enemy hitboxes were a bit unforgiving at times but you get used to it. Another suggestion would be to make the main menu text stand out from the background a little more, and that the sound effect for jumping is a bit disconnected from the music.
An impressive game with a unique theme, really well done!