Not during the game's events, or the backstory, but the protagonist Bucky Beaver is a cartoon character whose debut appearance is stated to have a premise of his accidentally buried alive. Only the title card (showing him lying in a coffin with his eyes open) and a brief synopsis of this fictional cartoon are seen.
An arm amputation occurs in the backstory which has an impact on some characters in the present. Another character had previously lost both forearms unwillingly.
The protagonist, Bucky Beaver, is mentally unstable, though his exact condition is not specified. He shows signs of depression and self-hatred, doubts his sanity, and briefly expresses a wish for death after reading something having to do with it.
One of the characters, Stumbler O'Hare, is a rabbit who lost both of his arms due to a wolf attack. The attack isn't shown, only mentioned. But Stumbler's wounds are visible with exposed bones.
While there's one in the files of the old version of the game ("Legacy Edition"), it's unused and inaccessible without hacking. It's absent from the latest release entirely.
One character (who even naming would be a spoiler) is very heavy on body horror and is horrifically mutated, with fused-together fingers, multiple jaws, and teeth where their left eye should be.
Even in "2023 mode", which is otherwise free of horror elements, an enemy called Hornz causes a jumpscare if one minigame is failed. In "1997 mode", jumpscares happen from multiple sources in the latter half of the game.
The game can open up websites, and two of the characters have an interactable website. Bucky, the main character, sometimes talks to the player directly.
While some have objected to one word used by a character (the name of a flower), the word has multiple definitions with the derogatory one being significantly less common and the intended meaning being "coward".