Thank you so much for taking the time to play it! I really appreciate the feedback, and agree with a lot of it. I've never been so good at level design, especially when it comes to building around a single idea, and even felt myself that a lot of the sections were quite finicky or needlessly hard.
I should have picked up during testing that the end of the level wasn't clear, and should also have figured out that it wasn't clear enough to the player that the box was an indicator of the length of the dash. However, I am very glad that you think that the core mechanic is strong - I felt this way too, but my level design and overall design in other areas didn't showcase it very well. This game definitely needs improvement, but thanks to you, I know that it can improve, deserves to improve, and how to improve it.
Thank you again!