- Aroused by Their Voice: His first words are to not let his "sultry" voice confuse or alarm you.
- Deadpan Snarker: It basically runs on this trope.
- Eldritch Location: Besides being a sapient, talking geological formation, the place can contain multiple separate biomes with locations from hundreds of years apart underground, going down it all the way somehow sends you back to the top, and if you keep what you came for, the ladder to the surface is implied to be endless.
- Genius Loci: As he's a living cave.
- Interactive Narrator: Played with; while he functions very much as one, it's made explicit from the very beginning that he is an actual character in the game world, he just happens to be a faceless seemingly-omniscient being with an omnipresent voice like most narrators.
- Jerk with a Heart of Gold: He has a rather cruel sense of humor and oftentimes makes jokes that are in bad taste, but he seems to have the player's interest at heart. He encourages them to look past the failures and see what lessons there are to be learned, and maintains faith that when the player makes their own journey into The Cave, they'll be ready to make the right decisions.
- Journey to the Center of the Mind: The game is this for both the cave and the characters. It seems to be very much telepathic, as it presents precisely those defining circumstances to those characters who choose to enter it.
- Lemony Narrator: As a narrator, he's prone to snarky jabs.
- No Fourth Wall: As shown at several points, the cave addresses us, the players, as fluently as the characters. Maybe more so.
- Seen It All: So says Mister Gilbert."Because of the amount of people that he's seen coming down here and their descendants, nothing surprises him anymore. Everybodys been down here at some point or another."
- Unreliable Narrator: Its Sarcasm Mode in full effect may make it seem to be this, but in the end, it's totally accurate to each character's choices.
The humans in general
- Anti-Hero: In the Good Endings, if you instead interpret it as the characters having refused to make the evil decisions in the past, despite all the villainous build-up, backstory, and inner demons, and the journey into The Cave was just a review of that history.
- The Atoner: In the Good Endings, if you interpret it as the characters having made the bad decisions in the past and regretted them after the journey into The Cave.
- Character Development: Either the character development happened during the journey, or the journey merely reviews character development that already occurred. The bad endings depict them having succumbed to inner demons in the past, and either dealing with or choosing to ignore the fallout of their decisions. The Good Endings show what is either them biting down on their inherent flaws at the last minute, or their expressing sorrow over not doing so (it's ambiguous which actually happened). Either way, they leave The Cave with an appreciation of moral consequences.
- Double Meaning: All of The Cave's introductions for the characters become a lot more sinister once you see what they are entering The Cave for.
- Flat Character: During gameplay, they're all unnamed, mostly have fairly generic apparences, don't speak, and never visibly react to anything that happens, even during their own chapters. They do get a bit more characterization in cave paintings.
- Heroic Mime: The flashbacks make it clear they're capable of talking, but in-game they don't say anything.
- Villain Protagonist: All of them except for, arguably, the Knight and the Hillbilly are doing cruel things for selfish reasons.
A man in full plate armor, whose helmet completely covers his face. Can create a barrier around him that is immune to all damage, but he cannot move while it is active.
- Barrier Warrior: He is able to erect impervious barriers.
- Epic Fail: In his bad ending, as a result of trying to take down the dragon, the entire kingdom goes up in flames.
- Excalibur in the Stone: His object of desire. He can't pull it from the stone until his partners use some dynamite to loosen it.
- Legendary Impostor: He's actually a peasant who stole the armor from the real (late) knight.
- Multiple Endings: If the knight chooses to take the sword from the cave, his ending is to burn to death along with the king and the country when the dragon attacks. If he leaves what he desires most behind, then he reveals who he really is to the king, who subsequently prepares his soldiers for battle instead of depending on an irresponsible boy to save him.
- Reality Ensues: His bad ending shows him trying to pull off the usual trend of kids or young men slaying dragons with confidence while ignoring the logic that they aren't trained properly. This ends the way reality would portray; the kid fails horribly and ended up with himself and his country destroyed. The good ending shows that it would take experienced, well-trained, and strong men to defeat strong dragons.
- Standard Hero Reward: He seeks the hand of the princess. He never actually gets her, but he does get a little kiss for his honesty in the good ending.
- Sweet and Sour Grapes: In his good ending. Despite admitting to his lie of being a knight, the peasant does get a little peck on the cheek from the princess for his honesty.
A guy with a pair of blue overalls, a thick red beard, a straw hat, and no shirt. Capable of holding his breath to swim deeper and farther than any other character.
- Does Not Like Shoes: His character model has huge bare feet.
- Freudian Excuse: He's clearly shown to have suffered from Parental Neglect. It's also why he's so sure a pink teddy bear will conquer his "true love": he had the same as a child and it was his only friend.
- Love Makes You Evil: His heartbreak on being rejected leads to him burning a bunch of people alive.
- Multiple Endings: Based on whether he takes the big Pink Bear out of the cave; he either burns down the carnival and goes on a crime spree, or he meets a new girl and finds happiness.
- Pyro Maniac: In his bad ending, he burns down the carnival, and then goes on a spree, burning down county fairs and carnivals across the country.
- Second Love: In his good ending. After being rejected by the glamorous circus performer, he meets up with a simple country girl, finds happiness, and raises many little Billhillies.
- Security Blanket: His pink teddy bear.
- Super Not-Drowning Skills: His ability is being able to swim around without eventually drowning.
From The Future comes this neon-decorated young woman. She comes determined to fix the past to save her future equipped with the ability to phase through small barriers.
- Disproportionate Retribution: She killed the progenitor of a family dating back millions of years simply because her current generation's member won Greatest Employee of All Time at the Mega-Corp where they were employed, and he may have lorded it over her.
- Driven by Envy: Her envy of her coworker, who was crowned Greatest Employee of All Time.
- Flash Step: Her special ability.
- Multiple Endings: Based on whether she takes the Greatest Employee trophy out of the cave. She either returns to congratulate her coworker, or she accidentally causes a bad future.
- For Want of a Nail: While killing her fellow employee was certainly nothing small, it ends up causing a Bad Future in her bad ending.
- Graceful Loser: In her good ending, she returns to the future without changing the past and gives the Greatest Employee heartfelt congratulations.
- Hartman Hips
- Reality Ensues: She thinks killing her rival's ancestor from the stone age can remove his existence. She really doesn't know that a caveman can be an ancestor to, let's say, great and important people who made her future possible, and her rival isn't the caveman's only descendant.
- Science Is Useless: Man, those hover-boots sure are flashy. Too bad they don't let her do more than float a couple inches off the ground and still subject her to every other gravity-based issue the other characters can have.
Plump, female, highly intelligent, very morally questionable aims. Can use SCIENCE! to subvert various control panels and other devices.
- Every Man Has His Price: Her bad ending shows her taking the money, and living a life of luxury while nuclear war erupts behind her.
- Greed: For no stated reason other than cold hard cash, she assisted in the launch of a nuclear missile which killed over a hundred million people.
- Hollywood Hacking: Her special ability is to hack into machines in the cave.
- Kick the Dog: The guidance system for the missile? A little monkey which she coaxed into his place with a bunch of bananas.
- A MacGuffin Full of Money: Her Object of Desire.
- Multiple Endings: Based on whether or not she takes the briefcase of cash from the cave. She either rejects the offer of cash and uses her brilliance to benefit society, or she takes the money and leaves the rest of the world to ruin.
- Screw the Money, I Have Rules!: Her good ending shows her rejecting the military's money and using her nuclear science for the benefit of society.
A lady adventurer from the days of exploring old tombs in search of her fortune. She can use a grappling hook to swing across gaps and climb up to platforms inaccessible by others.
- Action Girl: She regularly gets into dangerous situations during her expeditions, and expertly avoids all of them.
- Adventurer Archaeologist: An archaeologist of the Indiana Jones variant, going into booby-trapped tombs for treasure.
- It's All About Me: Her selfishness is not only a part of her story arc, it's part of the gameplay, where her companions the other player characters are almost impaled on spikes because of how she progresses through her area, and the cave wonders if she'd even care if she realized.
- Karma Houdini: In her bad ending, she kills her 'friends' with a dynamite explosion, and claims all the money and glory for herself. No retribution here.
- Multiple Endings: If the Adventurer leaves the cave with the gold coffin, Bad Ending. Otherwise, Good Ending.
- The Power of Friendship: In her good ending, she warns her friends about the traps, makes up, and learns to share the rewards.
From Victorian London come these two very eerie, quiet children, a boy and a girl, with glowing eyes. Can leave behind ghosts of themselves to hold switches in place.
- Creepy Child: They look like little ghouls, with grey skin and glowing eyes. They're also homicidal.
- Creepy Twins: These quiet, creepy children are constantly at each others' side and act as one individual.
- For the Evulz: The Cave suggests this might have been their motivation for killing their parents.
- Half-Identical Twins: They are a boy and girl, yet look exactly alike.
- Hoist by His Own Petard: In their bad ending they poison their parents' food, but are forced to eat the same meal and die as well.
- Self-Made Orphan: Why they are in the cave. They wish to poison their parents so they won't be held to any rules.
- I Just Want to Be Free: With the darkest possible tone. When they felt too oppressed by their proper, upstanding (but very loving and reasonable) parents, they simply killed them with rat poison.
- Kick the Dog: Their parents bought them each ponies, which both died in a "mysterious" barn fire.
- Multiple Endings: Based on whether or not they take the rat poison from the cave. They will either be forced to poison themselves, or they'll make up with their parents.
- Spoiled Brat: Listening to Daddy may cause him to say that he will each buy them another pony if they're good.
- Tears of Remorse: In their good ending, they warn their parents not to eat the soup and tearfully hug their parents at the end.
A Tibetan-style monk who always seems to be at peace. His ability is to use telekinesis to grab or manipulate out of reach objects, even through walls.
- Always Someone Better: The master was this for him.
- Deceptive Disciple: He hides his frustrations with his training and plots to kill his own master.
- Epic Fail: This guy failed to have any of the traits of a true monk. No wonder he was passed over by his master.
- Klingon Promotion: His ultimate goal. He kills his own master to succeed him as the Dark Master, rather than actually work to achieve enlightenment.
- Mind over Matter: His special ability is to use telekinesis.
- Multiple Endings: Depending on whether he takes the Meditation Statue out of the cave. He either kills his master and succeeds him, or works hard and achieves inner peace.
- Tame His Anger: In his good ending, the monk continues struggling to gain enlightenment, and eventually learns inner peace.