Simulation Game Theory
This game is a simulation used to train professional assassins/executioners on the dangers of psychological manipulations from the targets/condemned. The game also indoctrinates the assassin/executioner into following orders no matter what.
In-Universe Allegory for Abusive/Toxic Relationships
The events of the game are meant to show what negative relationships can be like, with mental and physical anguish on one or both sides, along with those who peer into the relationship. People may give advice, advice which may fall on deaf ears. The Princesses many forms also add to this, showing the many dimensions or 'faces' an abuser or victim can have.
In-Universe Fiction/Story
A bit meta. While the events of the game are
obviously fiction, being a video game, this goes a step further and says that it being a fiction is apart of it's in-universe lore. The Creator is implied to have been a mortal man, having 'created' everything in the universe. Before he passed away, he created the Narrator to continue his work. Whether or not the Creator is a human or not, or actually died or not, the events of the game could simply be an abandoned story, with the Narrator being someone trying to finish it the way HE wants, or the way he believes the Creator would have wanted.
The Narrator isn't actually a bird-like creature
The only time we 'see' the narrator is when the Player is looking at a mirror, looking at his own bird-like appearance. The Narrator is puppeteering our own reflection to talk to us. He even explicitly says how he is a different entity from us, although it's unclear if he means it for anything besides the Echo thing.
The Narrator chooses to die/commits suicide every time the Player dies or Construct ends
The Narrator wasn't created to be a replacement to the Creator. While he
does fill a similar niche, its clear that his purpose is to end the Princess and nothing else. Considering that in any world where the Player dies or Construct ends constitutes as a fail for him, it makes sense that he sees no more reason to live.
The end of the world will happen because of the princess's nature
The princess is being truthful when she says she has no desire to end the world, however she is immortal, and a being that changes depending on how she is perceived. Inevitably, someday, someone will perceive her as having both the desire and the ability to end the world, and she will become that person.
The Voices reflect the Princess's perception of the Hero
The Princess's Chapter 2 forms seem to be a reflection of the Hero's perception of her. It's possible the reverse is also true, and every Chapter 2 Voice reflects what she thinks of him (smitten, paranoid, cold, etc.)
The Narrator doesn't actually die when the Player/Construct is destroyed, at-least not every time
The Narrator explicitly says that he is tied to the Player, and also that if the Construct or Player ends, then he ceases to be aswell. However, we see a few cases where the Narrator appears to 'disappear' before either of those things happen, usually from being scared or angry at the Player. He also appears to be pretty nonchalant about the "dying infinitely forever" thing. Granted, this could be from his nature as a higher-entity, and just simply doesn't care about dying, knowing that there are infinite amounts of himself who will continue the job.
The Voices don't grant the Player any extra power, they simply help unlock his latent powers
Some of the Voices grant the Player supernatural abilities such as being able to revive from the dead (without restarting a loop), gaining superhuman strength/speed/intelligence/willpower/fighting ability/senses, or being able to manually activate failing organs. However, even without the specific Voices needed for a specific ability, the Player is sometimes able to tap into them. While it's already confirmed that the Player is a god alongside the Princess, the Voices are aspects of his godly form that can help unlock his true powers.
The Player being a non-human race explains some of the physical differences between him and the starting Princess
The Player is a species that is much weaker than humans, being unable to contest with the Princess physically, but also being much harder to actually put down than a human, surviving wounds that would kill one numerous times over.
Granted, we do see the Princess break her way out of a metal chain a few times, but that could be explained by the next WMG:
The Narrator unintentionally alters the powers of the Player and Princess.
The Narrator has shown the ability to warp and bend the Construct to his whims, along with manually being able to manually pilot the player, however there is a bigger thing of note — Almost nothing in the story happens without the Narrator's commentary. He is almost never taken off-guard, and even while scared continues to commentate. Things that didn't see feasible for the Player or Princess to do suddenly become possible once he starts talking about them. If he says she's about to break free of her chain, she will. If he says she appears to become more beastly, she does. If he says the Player slays the princess, he probably does. However, it's unclear whether he only says these things because he KNOWS they're about to happen, or because they're happening BECAUSE he says them.
The Creator, and likely everyone else in the Universe besides the Princess are bird-like creature. The Princess is the 'monster' relative to everyone else
The Player is a bird-like creature. He was created from the essence of the Narrator. The Narrator is a bird-like creature. He was created from the essence of the Creator. Who's to say that the Creator isn't also a bird-like creature, as is everyone else in the universe? We don't see a single human that isn't the Princess.
Maybe also the Princess has various Voices
While when she possess the Hero in the Spectre form, she says that she doesn't have the Voices, it's also true that she was indeed the one to possess him and not the other way around, so maybe this was the actual reason for why we don't hear them while she's doing this but she's instead able to hear both the Voices and the Narrator, and when asked about them, she simply decided to lie and to hide the fact she also has various Voices. If true, it would beg the question of why she, or her Voices, or both, decided to hide this fact. And also it makes wonder who would be her Voices and when and what circumstances, like for the Hero, make them start to talk, and who is her first Voice.
The Voices are what remains of the Shifting Mound within the Long Quiet
The Creator made the Construct in an attempt to stop entropy by spliting the concept of the universe into two opposing entities symbolizing order and chaos respectively and pitting them against each other. As the Long Quiet, you are the personification of order and stability and shouldn't be susceptible to change, so why does a new Voice spawns in your head after each death? Because the Princess and yourself where once a single concept and as there are parts of you within her that keep her from changing without your perception to affect her, there are also parts of her within you that influence your actions based on how she perceives you. The difference is that those Voices don't change you unless you let them, whereas the Princess is always shapped by your perception of her.
The Mirror is a projection of the Long Quiet's subconscious knowledge of his true nature
The Narrator can never see it because it's not part of the Construct, even the Voice of the Hunted acknowledges that it's not actually here since he can feel the wind going through it. It's only perceivable to the Long Quiet because it's a part of him trying to make him realize what he really is, hence, a mirror. It's the only object that appears after the construct unravels because it's the moment the Long Quiet starts to acknowledge that he is not a mortal being, and seeing himself through it is what allows him to reach godhood.
The Narrator is actually not a separate being from the Long Quiet, but another Voice, despite everything that suggests he is.
In the "Reset The World" ending, the Princess erases our memory and starts over. At this point in the story, the Narrator has faded away with the Long Quiet's understanding of its true identity, so how is he recovered when the world restarts? He isn't. The Narrator we hear is no longer the Narrator we may have started with, but another Voice of the Long Quiet assuming His role. Perhaps at one point, the Narrator was once a human, but the Echo of that human has long since faded away, only to be replaced by the Long Quiet that is used to his constant presence.
- In this ending, the Princess and Slayer mention the possibility that they've gone through this cycle countless times, having met, been unsure of what to do, and restarting to get another chance at a happy ending. In this light, it's entirely possible that every version of the Narrator and the Creator we meet is merely an extension of the Long Quiet playing the role of an omniscient storyteller. This could be part of why the Narrator struggles to answer in-depth questions, and why the Creator never goes into detail about his true identity as a human. The Long Quiet doesn't actually know much about the one who created him, and gives the same recycled lines he heard long ago.
Every ending is canon simultaneously.
Both the Princess and the Protagonist are creatures of contradiction, after all.
