I think this is a wonderful game! I especially love the artwork.
I think it could be even more fun with a slightly faster pace!
I didn't really notice it when I cleared it in one or two tries, but after a few failed attempts, the echolocation started to feel a little slow. Maybe having an option to adjust its speed or skip it would make repeated attempts feel a bit smoother.
That said, if the current speed is important to the overall atmosphere of the game, I think it's probably the best choice for the default setting.