Really great entry! Hit credits, but didn't find any secrets. A lot of solid puzzles and it's always fun to have "knowledge gates", feels very cool. And I think you did a great job with the theme by getting so much mileage out of "one" ability. I don't want to say too much and spoil anything.
Minor issues, the sound effects were so much louder than the music, that I could barely hear the music in order to have the SFX at a comfortable volume. And having to figure out both (?) hidden techniques so close to each other, was a lot of frustrating trial and error in a short span of time, maybe they could have been spaced out a little more. They were very cool though!
I think my biggest struggle is just the structure of the world / game. Each area is mainly a puzzle gauntlet, through which you gain some knowledge that can be used to access the next puzzle gauntlet. And there's not much reason to go back through those old areas. As a result, the game felt pretty linear. It did open up a tiny bit at the end to find the remaining blocks. And this is certainly not an easy fix while creating this style of minimalist puzzle game. But I just missed the sense of world and exploration you get in a "normal" metroidvania.
But this is a really good game, you could easily expand / polish it a bit and it's be ready for sale. Tremendous work!!