I wish I could leave a mixed review instead and this game looked promising, but... I love exploration or walking simulator games, but there are little to no substance other than a few empty corridors, a huge open space and "Hey, here's a level that looks like it's from Super Mario 64!" Really... if you're going to go for an exploration game, encourage and reward people for it and don't just let people walk through a linear corridor where there is nothing to enjoy and do besides looking for an exit to the next level. The pleasing visual style you coat the game with won't help the game at all.

Moreover... for a platformer game, it's pretty basic and easy but most of the game are just empty mazes which serves no purpose to the game (ehem, game-length padding). This game feels more like a glorified demo. Other than that the story is alright, but that's about it. Shrugs for No-Face Wannabe. [6/10]

A lot of people talk about this being like Yume Nikki or other walking simulators, but it really seems to be doing something different. I enjoyed playing it for what it's worth, but it's a bit of an odd mishmash.
It's got atmosphere, that varies from light and airy to rumbling and oppressive. It alternates between good 3D platforming and tension-building exploration sparsely sprinkled with jumpscares.
The environments are the main character in games like these, and they range from what I assume to be original, light-hearted, open, and creative, to small, referential (there are quite a few levels later on that are sections of Mario 64), empty, and foreboding.
Me personally I'm not a big horror fan, so I really wanted more of the light-hearted areas, and the platforming had a good feel to it. To the point I was thinking to myself that they would have spent their time better just building an unabashed 3D platformer.
There's some plot going on, and honestly it isn't hard to follow per-se, but it's a little barebones, with so few kernels of info to connect together that who is to say what it exactly means other than the general idea of a haunted game.

tl;dr if you like atmospheric walking simulators, you might not want the horror story elements, but if you're patient it's still a fun experience.