Overall the game is really beautiful and generally fun! However, there were some bits that felt too precise or where I was unclear on where I had to go. For example, the part with the small red crystals on the minecart track was really unclear about where I was supposed to be jumping, and on top of that the crystals in the downward sloping cave right before requires really tight jumps to get through that brought a good amount of frustration to the game. Also pushing block puzzles don't really work as well with this perspective because I can't really see where there's empty space to push the blocks.
Some general things I would recommend: The ability to control the character in the air would make the controls feel a lot less slippery. And making sure to keep the ceilings generally high in platforming areas so that the player doesn't bonk their head on the ceiling, sending them down unpredictable and uncontrollable paths.
Also, though I would've loved to beat the game, I suffocated before I could and lost a lot of progress. Very disheartening.
Despite running to these issues, I really enjoyed playing the game! I really loved the environmental storytelling; I think it has a lot of potential.