The people were down on their luck. Their crops were dying.
Then God spoke to them.
Their current church has an inscription that says that God stops death, so he very likely told them he could save their crops.
So some of the people became Devotees of the God and went to where he was calling from. They arrived at a tower-like structure where they believed him to be, but they were blocked from going inside by some guard Warriors.
The Devotees now live in an abbey they've constructed here at the base of the tower. So I guess they've been pilgrims here for quite a long time (long enough to build this abbey complex at least) and have never been permitted to visit God.

The child that helps us get into the abbey said he/she is "not free" before they went into the abbey. We don't see any sign of them after that. (Or do we?? Read to the end!)

The Preacher that seems to be in charge of keeping the plants in the garden alive and speaking to Devotees in the church found a lens that he thought would help him find God. He brought it to the cemetery and went into the hidden passage that does, in fact, lead to the next level of the tower, but he ended up somehow dying in the underground area. (It looks like he just fell, honestly. Poor bloke.)

It seems the Warriors were "called" here to the tower. (Presumably by the same entity that called the Devotees over.) When they arrived, they discovered some other people already here that we later find out are called the Bards (but the Warriors call them the Chosen). The Warriors admire the Bards and their music. So they decided to stay here at the tower and build a fortress. They've taken up a "duty" to keep away the "Impures," who are pictured as demons, and to protect the Bards/Chosen.

The Warriors consider the Devotees (who arrived after them) to be "Impures." (However, now that the Warriors know the Devotees can play music just like the Chosen can, they have a new respect for them!)

They also seem to be exporting bottles of alcohol and crates (of something?).

The Warriors not only have a mantra to obey their duty but also that they must "await the call of the Chosen." When the call is made by ringing a special song at the belfry, all the Warriors gather in the square, and the Bards (with our help) came to play music for them!

Arriving at the Garden, a sign says that Bards are allowed in, but not Warriors. The Bards are a carefree, leisurely, creative people. They say they want for nothing, and it's apparent they therefore can pursue vapid interests/vices and creative pursuits.

They think anyone trying to ascend to the next level of the tower is an idiot (because they know there is a deadly monster blocking the way).

They also call the people with blue masks idiots. The blue-masked seem to be a lower working class. We learn later that they are called the Serfs. With our help later, the Devotees end up inviting the Serfs to the abbey so that they can be free men instead of work-slaves in the garden.

Leaving the garden, you encounter a monster in an abandoned mine. Once you manage to get past the monster and go up to the next level of the tower, you get to an industrial laboratory area where the Scientists are. They are trying to use alchemy to forge a key which will open the "Fairy Door." There is a mural in the library that says that the Fairies "turned the door on."

We find out later that the abandoned mine the monster was in used to be the Scientists' copper mine, which they have since closed off.

A chat between a Scientist and a Warrior reveals that the Scientists wish to *help* the monster and that they're afraid of it and that they do not want to die. The Warrior then replies that they are not afraid of monsters and will help them. The Warriors help them catch the monster, and in Lab 1, it appears the Scientists are looking for a way to transform the monster into a regular man, which implies it was a regular man to begin with! This is reinforced when you go to Lab 3 where it looks like an experiment had gone wrong and caused the scientist or test-subject there to transform into a monster, and it appears they then escaped down through a hole, likely down into the mine. (Thanks, ElizatronicWarfare and McFugglet for helping clarify this part!)

The Scientists and Bards are considered "brothers." A book shows that people go through a spark of some kind (symbolizing enlightenment?) and become either one or the other. They represent the Arts and Sciences.
There is also a mural that says the scientists seek, but that the bards have found. Some of the bards talk about how they don't seek or want anything, for they have found beauty and are thus fulfilled. Whereas the Scientists are seeking a way through the Fairy Door, probably to ascend to the top level of the tower.

When we unlock the "Fairy Door," we get to ascend to the top level of the tower, where the Anchorites (probably who the Scientists call "Fairies") live. According to a story we're told by one of them, they're the ones that made the tower to begin with, then all the other people came. Since all these different people were strangers to each other, they were afraid to talk with one another. Out of fear, the Anchorites went into recluse mode and immersed themselves in a virtual reality world. He then explains that his people are dying, and the tower is dying too. He explains he created you (the visitor) to help them by getting everyone to start talking to one another so they can stop being afraid of each other.

Apparently, the "God" that called out to the Devotees and Warriors is an entity known as "Exile." Exile is also the one responsible for enticing the Anchorites into drowning themselves in the VR system, which Exile has complete control over. Exile is basically enslaving the Anchorites and sucking the life out of them. It wants more people to come to it, which would explain why he called out to the other peoples to come to the tower.

Because the god's name is Exile and the Anchorites call themselves the "people of exile," it's implied that's why they came to this place to begin with. They were banished from some other place, and so when they got here, they built this tower as a new home for themselves.

After getting all the peoples of the tower to communicate with each other and disabling all of Exile's control posts, we ascend to the very top spire of the tower. There, we are captured by Exile's robot henchmen and hooked up into his VR world. We find out that our child friend from the abbey was also captured and put here. They come to our aid again and help us find our way around inside the VR world.

Things are a little different in this bizarro version of reality. In the play in the Bard's theater, when the fool is supposed to encounter the monster in the copper mine, they don't. Instead, they find a Scientist, which means the story has changed, and this time, the fool made it to their level successfully. Other changes in the VR world reflect some other things we have made an impact on in the tower. The Warrior's mural now says the Impures (who are the Devotees) make music. A mural at the abbey (although disassembled) now shows the Scientists made a potion, which we know was to help the plants stop dying. (This means the Devotees no longer need "God" to help them with their plant problem, the whole reason the Devotees came to the tower to begin with).

Eventually, God/Exile gets tired of us thwarting his creation and sends some monsters after us. We get away with the help of our child friend and then find our own body hooked up to the VR matrix. By turning off the terminal we're connected to, it somehow also kills Exile and shuts down his entire VR world.

Back in the real world, the head-transmitter thing at the top of the tower is no longer sending and receiving signals (I can't help but be reminded of the "Big Giant Head" from "3rd Rock from the Sun" lol), and all the Anchorites are freed from their devices. Everyone gathers at the top of the spire and we live happily ever after!

It's not entirely clear what the Anchorites' backstory is. Were they in-fact exiled? Why? From where? Did Exile come with them, or did he come to the tower and take over later after they built it and were already living here for a while?

Where did the Bards and Scientists come from? The book in the library implies they sort of transformed into one or the other (from regular men, maybe?). Were they originally Devotees or some other group of men altogether?

Why are the Warriors seen constantly exporting alcohol and crates (of unknown contents)? What are they up to? Where are the goods coming from? We don't see a production area anywhere, just storage and shipping.

Feel free to discuss the story with us in the comments! :)