Thanks for playing!
The jump arc / movement in general is something that I need to address. One big issue with it is how if you hit the side of a wall it will cut the jump short, which I noticed causes players to miss a jump that they otherwise should have had the height to make, which is very unsatisfying.
As for the windows of visibility, I will be tweaking some of the variables involved such as the duration and speed of the sound wave. Honestly I had intended to have the waves last a bit longer and fade out slowly, but that seems to require a shader which I am not yet familiar with. Spent a couple of hours trying to create a shader but I think I need to learn them from the ground up to understand why mine didn't work and how to make it work.