After completing it, i can say it was a lot of fun overall. The exploration was intuitive (for the most part, i'll get there in a moment) ,the levels were well designed, the secrets were well crafted and the boss fight was challenging but fair (or at least, i felt like it). Also the "echo" mechanic was creative, reminded me a bit to Braid. It has potential to be expanded for greater puzzles/challenges.
That being said, my biggest criticism is the movement. While it feels ok on ground, It gets very floaty on air and the jumping physics felt very inconsistent, sometimes feeling as high as they need to be, and other times feeling very short, which makes platforming and exploring more difficult than they should be.
Another criticism is the audio. The music is great, but the sound effects are louder than they should be (as good as they are).
In general, i really liked the game, hope it gets more attention and gets more improvements in the future.
P.D: The accessibility option was a nice touch.