Beautiful atmosphere, the art and music fit together very well. For the most part there's a lot of fun to be had with navigating with the cord. One of the first things I did by accident was skip nearly the entire first vertical corridor by effectively using the cord as a bungee. Sometimes the bungee worked really well, and when I was able to get it to work it was super satisfying. Other times, it didn't seem to want to let me gain that much upward momentum no matter what I did.
There were some peculiarities with the collision, it felt like some corridors were a little too narrow to navigate well with the player character. I also wish that there was some kind of ability to control the force behind throwing the cord, since a frequent roadbump I ran into was the cord just bouncing off a surface or zipping over an edge before I could climb onto a platform.
Overall, very clean execution. Great job