Beware of spoilers!
TravelersPeople who have journeyed beyond Timber Hearth.
You, "Hatchling", "Time Buddy"The protagonist, a Hearthian that the player controls. While on their first solo flight, before which they accidentally and unknowingly pair with the Nomai statue in the Observatory, their Sun suddenly goes supernova and explodes, destroying their Solar System. Now trapped in a time loop of 22 minutes before the end, they must discover the source of the supernova.
- Everyone Calls Him "Barkeep": Every Hearthian NPC refers to them as "Hatchling".
- Groundhog Peggy Sue: The entire point of the game is that the protagonist pieces together the clues of what the Nomai were doing over multiple loops, hoping to find a way to save everyone.
- Heroic Mime: Zig-zagged. At first glance, the protagonist seems like another blank slate for the player to assume the role of, as they appear to have no direct dialogue with the other NPCs. But it turns out that the response options you choose when engaging with NPCs are their dialogue, and many of these options are filled with personality. Furthermore, if you set out for one of the Spacetime endings by jumping into the black hole inside Ash Twin's core at the end of the loop and then meeting your temporal duplicate in the same location, you'll find that the duplicate is perfectly capable of speech, turning the trope on its head.
- Uncertain Doom: The only Hearthian not consumed by the exploding sun, they might meet their end from the new big bang but the Eye of the Universe conforms so little to standard paths of logic that their fate is essentially a mystery.
EskerOne of the first astronauts, currently residing on the Lunar Outpost on Timber Hearth's moon.
- The Aloner: Improvements to rocket technology means nobody needs to use the Lunar Outpost anymore, leaving Esker alone on the moon.
- Captain Crash: Is well known for crashing their ship.
- Bunny-Ears Lawyer: Despite their casual attitude about pretty much everything, they're still a genuinely skilled and knowledgeable astronaut.
- Groundhog Peggy Sue: They've been in the loop just as long as the protagonist, but they aren't interested in fixing it.
- Meditation Powerup: They developed the meditation technique that allows you to skip to the next loop.
- Unfazed Everyman: Gabbro is laid-back to the point of vegetation. Their island being thrown out into space by a hurricane is at best a minor inconvenience, and even being trapped in an endlessly repeating time loop seems to barely perturb them.
- Despair Event Horizon: Crosses it by the final minute of the loop.Chert: Come, sit with me and watch the stars die. [...] How unfortunate, to be born at the end of the universe. Any minute now...
- Face Death with Dignity: Calms down from their previous manic state and embraces their impending death in the last minutes of the loop.
- The Napoleon: Downplayed, as they are not very egocentric or aggressive, but they are snappy with the player and prefix all of their audio logs with, "Chert's Notes - Property of Chert!" They're also the shortest traveler you meet.
SolanumThe last Nomai in existence, she traveled to the Quantum Moon during her pilgrimage, but has been stuck there ever since thanks to the Interloper exploding ghost matter across the solar system. If found in any of the five locations the Quantum Moon orbits, she'll be long dead, but if found in the Sixth Location near the Eye of the Universe, she'll be alive, and you'll be able to converse with her.
- The Faceless: Her face is hidden behind a Nomai mask that forms the headpiece of her space suit.
- It Has Been an Honor: Her last lines.Solanum: A conscious observer has entered the Eye. I wonder what happens now. It is time to find out? ... This song is new to me, but I am honored to be a part of it.
- Last Of Her Kind: She is the last surviving Nomai of Escall's clan, thanks to the Interloper rupturing and releasing deadly Ghost Matter throughout the system in which the clan was stranded. There were other clans outside of the system who weren't affected by the Interloper, but the player is unable to contact them, and the impending heat-death of the universe means they're likely to be extinct shortly if they aren't already.
- Schrodinger's Nomai: Due to the Quantum Moon's unusual properties, Solanum exists in all six of its locations, but due to the ghost matter that irradiated the entire system 281,042 years ago, all but one of them are dead, her corpses lying in the moon's south pole. One version of her managed to reach the Sixth Location before it was too late, but due to the Moon's atmosphere becoming an impassable barrier, she's trapped there. She can't even die of old age as time doesn't work in the Moon.
- Time Abyss: Due to the weirdness of the Quantum Moon, she's existed on the sixth iteration of the moon ever since the destruction of the Nomai race 281,042 years ago, both alive there and yet dead on the other five iterations at the same time- although it's implied that for her no time has passed at all.
Hearthians in GeneralA race native to Timber Hearth, and the only sentient life still in the solar system.
- Extra Eyes: They have four eyes compared to the usual two- the museum notes that to them, the Nomai "only" have three eyes.
- Fish People: Though they have fish-like characteristics, the Hearthians have evolved beyond that and cannot breathe underwater.
- Non-Human Non-Binary: Hearthians don't seem to have more than one gender, as none of them are referred to with gendered pronouns.
- Rock Theme Naming: All of them are named after minerals.
GneissA Hearthian musician who created the instruments used by the Hearthian travelers.
HalA Hearthian engineer and close friend of the Hatchling, who built the Nomai translator.
- Bait-and-Switch: Most of their notes on the Ash Twin Project discuss the possibility of accidently destroying the entire solar system, pinning them as the number one suspect behind the sun's sudden supernova. Once you get to the Sun Station their project notes reveal the project was a dud and abandoned - the Nomai are completely innocent.
- Beast Man: They're humanoid goats.
- Benevolent Precursors: Though they didn't directly create the Hearthians, their technology is scattered throughout the system and may have inspired the latter's penchant for space exploration. They showed a great deal of respect towards other life forms; when they discovered that life had evolved on Timber Hearth, they make sure to leave behind some metal deposits so the newborn species (all but stated to be the ancestors of the Hearthians) could eventually develop technology of their own. One of their arguments against the construction of the Sun Station was that any mishap could cause the destruction of all life in the system, including the Hearthians.
- Crystal Spires and Togas: Their structures and vessels have a smooth sandstone-and-gold motif giving them an ancient look, and they're depicted in murals wearing robes and elaborately-carved masks. The appearance of Solanum indicates that not only are the murals accurate, but they depict what is essentially a Nomai space suit.Escall's Vessel shows their tech was even more advanced when they first arrived in the system, and had to rebuild from the ground up when they were stranded.
- Extra Eyes: They have three eyes, with the third above the other two. The third eye is apparently more sensitive than the others, but it's not specified by how much.
- The Faceless: We never actually get a good look at one in the flesh; all that's left of them are murals and skeletons and Solanum, who wears an all-covering space suit.
- Floral Theme Naming: Most of the named Nomai in the game are named after plants.
- Higher-Tech Species: Their technology has a strong Crystal Spires and Togas aesthetic, and it utterly blows Hearthian tech out of the water with inventions like FTL travel, artificial black holes, and spacetime manipulation.
- Legend Fades to Myth: As seen on the transmissions caught by Escall's Vessel, his clan has faded into legend, with only a few Nomai remembering that they really existed. Given he and his clan's Vessel disappeared over 280,000 years ago, it's understandable.
- Mind over Matter: They seem to have had a limited form of telekinesis; it's unknown if this is a natural trait of their species, or a result of their advanced technology.
- Not Quite Dead: The Nomai race is still alive elsewhere, as other clans continued to travel the universe long after the Vessel's disappearance. Unfortunately, as the universe is on the verge of death, their days are numbered. By the time the player reaches Escall's vessel, the last remaining Nomai clans are gathering to face the end together.
- Proud Scholar Race: The Nomai were a peaceful race who took great pride in their scientific knowledge and penchant for space exploration. Prominently displayed in the conversation with Solanum: if you choose "Identify/Explain", she notes that these two concepts are the core of Nomai philosophy, and if you choose "Explain/Me", she tells you that she'd ordinarily have countless questions for you, were it not for the language barrier.
- Space Nomads: They were apparently organized into wandering "clans" that met every ten years to share their discoveries. The ship that brought them to the Hearthian system was the vessel of Escall's clan.
- Starfish Language: Their language is written in spirals of characters, with different dialogues or trains of thought branching off from each other, resulting in a structure of nested conversations diverging from a common root.
- 0% Approval Rating: Everyone either hates or fears these freaks, including the Eye of the Universe itself.
- Alluring Anglerfish: As the name suggests, the lure on their heads is meant to mimic the light of Dark Bramble seeds, so you accidentally fly into their mouths instead of elsewhere in the Bramble. The heavy fog helps disguise them until it's too late to turn back.
- Hell Is That Noise: They make a terrifying screeching roar when you make enough noise for them to fully charge at your location.
- Hopeless Boss Fight: They're invincible, faster than your ship, and won't forget about you if you get their attention. It is possible to survive them if you happen to be close enough to a Dark Bramble seed to transition to a new area, but you have to be pretty close to pull this off and you better hope it's the one you're looking for.
- Monster Is a Mommy: The three in the red seed are protecting an egg clutch, possibly explaining why they're so aggressive. Unfortunately, they're also guarding the only gateway to the Vessel.
- Alien Geometry: Appears as a black sphere, with the Quantum gas especially bizarre, though only if no one touches it.
- All the Worlds Are a Stage: When in the Ancient Glade, it will create Quantum objects and areas familiar to the player, as well as the planets you travelled to in order to round up the Travelers's instruments and prepare for the next Big Bang.
- Ambiguously Evil: As a child, Solanum believed that the Eye was a malicious entity that led people to their doom. Once she grew older, she moved on from those ideas.
- Ambiguous Situation: It's unknown just if or how sentient it really is, though there is evidence that It Can Think, given it uses the protagonist's memories to recreate Quantum versions of both the Observatory and the other Travelers. As well as its own disdain for the anglerfish species.
- Eldritch Location: Its physical appearance is unlike that of any other planet in the game. A barren grey world covered with stripes of black, basalt-like rock, devoid of life except for a few trees in its southern hemisphere, which sits on top of a wormhole several times bigger than it is. The wormhole itself is also weird, resembling a bright purple whirlpool with the angular pattern the Nomai used to represent it extending throughout its accretion disk. The wormhole causes a permanent lightning storm in the southern hemisphere of the Eye, constantly triggering the quantum states of its trees and the loose rocks. Right in the Eye's south pole, there's an iris-like crater where gravity inverts and drags whoever stands there into the event horizon.
- Everyone Has Standards: Even a Quantum object older than the universe itself hates the anglerfish species, and it breaks the Mind Screw just to apparently note that's it will be the race missed the least, as shown with the young one dead and a skeleton in the tank.Of all the lifeforms who will perish in the oncoming death of the universe, we will miss the anglerfish the least.
- Mind Screw: A whole bunch of weird things happens once you fly into the black hole that condenses the Quantum gas, and it's really hard to explain. The best one could make up would be that its attempting to communicate with you and using both the Ancient Glade and other Quantum objects, that the universe is ending and you must Restart the World.
- Quantum Mechanics Can Do Anything: Quantum shenanigans ensues once you touch the pit of Quantum gas, such as meeting yourself, which turns into a tree and then a campfire, and other events, when ever you look away or turn off your flashlight.
- Restart the World: More like universe, but that what its purpose seems like. Gathering all of the Quantum gas, it will eventually compress into a singularity and create a new universe with a Big Bang, destroying the old one in the process. While that may sound villainous, it's apparently only for the natural end of the universe.
- Weird Moon: Its satellite, the Quantum Moon also shares the planet's quantum properties and due to this, it exists in orbit of every planet in the system. It can also alter its appearance and take on the properties of those planets when it's observed. When it orbits the Eye, its atmosphere becomes impossible to penetrate except for the whirlpool in its south pole, which will randomly teleport the Hearthian to another of the Moon's locations.