Wow! I'll be frank: at first it seemed the usual 3D puzzle-platformer, but the more I played, the more I find myself enjoying this!
The idea of manipulating objects to build a path might not be the newest concept, but that's not important. But then: you built the idea of memories on top of that, and each memory is discovered along the journey, and the memories serve as checkpoints, and the memories tell a story which makes me relate to the character, and then the character travels across this world while I get to know their story, and there's a beautiful music in background that embraces the voiced narrative, and the pieces of the paths slowly come together like the whole story does, and... It's a lot.
In the end, I was amazed. It felt like it was perfectly balanced, with everything at its place and all the elements working together. In my opinion, balance is the strongest point of your game. Congrats :)
The only constructive comments I can do is that controls were a bit odd sometimes: having an isometric movement is not easy, especially when you requires the player to move along narrow corridors suspended in air, because two buttons are required at the same time (from keyboards). I imagine it's implemented in 2D, so rotating the environment is not feasible. A possibility would be to made the controls more precise, maybe with a clearer character's shadow that gives to the player a better feeling of where they are (at the moment there's a large cloud at the character's feet).
Another thing is that collapsing platforms are not too different (in color) from the standard ones. They could be unnecessary difficult to distinguish, especially when the vignette effect is stronger. But besides these two comments, the gameplay (and the game overall) is really good.
Congratulation, a really solid entry that I enjoyed a lot! Thanks :D