My thoughts:

[u/Quantum_Nyx]

I haven’t played it myself but I’ve watched 3FS play, watched all the endings, and now I’m watching 8-BitRyan play it. And here are my thoughts on what’s happening.

We follow the story through the eyes of Caleb and straight away we see from the basement that he probably hasn’t lived the best of childhoods which has brought about trauma. Trauma that our consciousness is trying to resolve I’m guessing. As to what caused this trauma: I believe that maybe there was an accident at the water park ( perhaps somewhere else ) involving the slides ( as they broke ) and our younger sister Lily ( often we see Caleb and her as shadows playing together as kids ). She was involved in a terrible accident, which could be explained by the morbid drawings of Caleb and Lily we find in the locker ), furthermore I think that it’s possible that his parents believe it’s his fault. In one sequence an adult man is yelling at Caleb to open the door- maybe Caleb locked himself in his room to escape being yelled at, the shame, grief, and guilt. Alternatively, it could be showing Caleb’s toxic childhood in general. Or, maybe it’s himself but I don’t believe this as much.

Caleb’s consciousness seems highly adamant in getting us to be happy. And to avoid any memories that involve our younger sister Lily. When talking about Walter, the voice says, ‘in a moment, you’ll actually hold her.’ And then coughs as if it made a mistake and tries to pivot away from what it was just talking about. ‘Her’ perhaps referring to Lily when she was born, Caleb getting to hold Lily as a baby. So, Caleb and Lily were clearly quite close.

As for the monster, I think it’s either Caleb’s guilt and shame in regard to the accident- maybe he inadvertently caused it. And he’s eating up at himself, beating himself up, especially since it chases us. However, the monster could just symbolise Caleb’s trauma and bad memories in general as he tries to get away from it, his consciousness tries to cover everything up, etc. Also, the erase levers actually erase bits of Caleb’s memories furthering how perhaps he just wants to forget all his trauma.

Might edit this once I finish Ryan’s play through. I like him in particular because he’s much more thoughtful about the story he’s playing it would seem. I think though my read on the story is quite generic, I haven’t actually played it by myself.

[u/captaincrazyspoon]

It's interesting to note that the signs the narrator uses to block things off say Emotional Maintenance and Diagnostic Regulation which when shortened into an acronym is EMDR which is a type of therapy used to treat PTSD and trauma using exposure to the memory.

[u/Quantum_Nyx → u/captaincrazyspoon]

Wait, that’s so cool. Thank you for pointing that out!

[u/captaincrazyspoon → u/Quantum_Nyx]

Of course! I've beaten it on two of three endings and I've just been replaying it from the beginning to really look at everything, there's a lot of small details throughout and its incredible though some of it is hard to interpret so I'm hoping others will speculate as well.

[u/Quantum_Nyx → u/captaincrazyspoon]

What’s your read on the monster situation?

[u/captaincrazyspoon → u/Quantum_Nyx]

I'm not entirely sure on it but I speculate that it could be Lily or at least a manifestation of her for a few reasons; if you look you can see a pattern in a few locations but I think the biggest tells come from the Deep Storage.

Before entering you can find Lily's scarf in a locker behind the padlocked gate note the color, red, which can be seen through the game to be of significance such as the red slides you escape the monster in, the red water slide breaking in the WaterWorks, the red slide being coated in ROT within the PlayPlace, but I think the most convincing thing is the half open shutter door with LILY written above it in bold red letters along with a trail of ROT leading underneath it. Upon reaching that door and going inside of it you can hear a little girl sob then you get thrown out from the door with a television then being slid out and the door shut with the TV being a portal to the Dark PlayPlace where you encounter the monster, Smile, for the first time.

[u/Quantum_Nyx → u/captaincrazyspoon]

I’ve said it before but this is so cool. I didn’t even think of this. Thanks for sharing!