Okay this is an excellent entry. Finished it with apparently one secret found (no idea what that was supposed to be haha) and another missing.
The first think that hit me was how well this game silently teaches its mechanics. I had originally written down that this quality disappeared later on as I would collect squares with no idea what new ability they gave me... but then I realized the squares probably never gave me any ability to begin with. I now assume everything was available from the start. So that's the part that could be clearer, probably by making sure the "tutorial rooms" are not the same as the "square rooms". But hey, I eventually figured it out. Speaking of innate abilities, I discovered two of them on my own and even used that knowledge to bypass one puzzle, so that felt good.
I like how each "branch" was dedicated to one mechanic. The one where you have to find increasingly convoluted ways to kill yourself was amusing. On the other hand, I could never pull out the "super jump" reliably, so that was more frustrating.
I almost gave up the game at the last two squares because I had no lead to explore. I wished I was able to freely look at the map rather than being restricted to snap from one "square room" to another. It makes it way harder to survey where I could go. I finally unstuck myself when I found a better map, to remain vague (you know what I mean). And then the last square was brilliant, the perfect note to end the game on.
Again, incredible work with this entry! Congrats, I wouldn't be surprised to see it win! ;)