Spoilers below!

Loved the concept, I wish the execution had a tiny bit more polish. First of all, minor nitpicks: The movement could feel just a tiny bit more floaty. Though I do appreciate that the player can sprint and jump instead of being forced to walk. Floating down mountains was especially fun. 

As for the game itself, I just wish there was something more. I saw this in some yt vid thumbnail and immediately had to check it out. At first I was worried that the thumbnail had spoiled bits of the game by showing some big face in the background. But turns out it was just the actual thumbnail used for the game here, so no big deal. Though, since it does turn out to be the face peaking at you from behind the mountains and also the one that ends up jumpscaring your, I think showing the "monster" like that in plain view on the thumbnail takes a lot away from the scare factor. I also really didn't like that you are locked behind an invisible wall. For the second play through, I tried to get a headstart as soon as I hit the switch but was locked behind said wall. I doubt I would have made it even if I started at that point, so why even have that there? For the rare speedrunner that actually makes it back in time, I think it would be more immersive to just stand around the ship rather than being blocked before you can even get there (or have some sort of trigger that activates as soon as you are back, which initiates an unlocking sequence which takes too much time, no matter how fast you are)

Though what I really loved about the entity is the implication that it tries to manipulate you to stay and possibly even repeats a song that the character is emotionally connected to, in order to make him feel secure.