Easter Eggs are references or nods to other horror games, YouTubers, and TV shows found throughout the game.
ScaryPlayerNorway A framed photo of him can be found in the randomly generated LP Room.
Band-aid Boy A framed photo of him can be found in the randomly generated LP Room.
Forksnapper A framed photo of her YouTube avatar can be found in the randomly generated LP Room.
Specimen 1 has many references, such as Jeff The Killer.
Specimen 2 is a nod to the Lub-Glub monsters from the cartoon Adventure Time.
Specimen 3 is a nod to the Resident Evil series.
Specimen 4 is a nod to most RPG maker/Asian horror games, more specifically Corpse Party, or Misao, due to her disposition and appearance matching Japanese folklore. Also she might be based on a famous creepypasta & urban legend Jane The Killer.
Specimen 5 and the sounds, textures, and ambience associated with it are a nod to the Silent Hill series.
The room Specimen 6 is first encountered in seems to be modeled after the Kakariko Well from Legend of Zelda: Ocarina of Time. Specimen 6 itself is a reference to the Happy Mask Salesman from Legend of Zelda: Ocarina of Time and Majora's Mask, or more specifically, the famous Ben Drowned creepypasta created after the game.
Specimen 7's design may be a nod to Giygas from Earthbound.
Specimen 8's design was inspired by The Beast from the cartoon miniseries Over the Garden Wall.
Specimen 10 (Old)'s design may be based on Onix from the Pokémon franchise.
Specimen 12 is a nod to the classic horror game Clock Tower.
- The Possessed One's appearance was inspired by the serial killer in the Adult Swim short, Too Many Cooks.
- Specimen 12's Steam card has art which is extremely similar to one of the rooms in Clock Tower.
Specimen 13's behavior was inspired by the Kaernk from Amnesia: The Dark Descent.
Monster 3's design may be based on Conrad from the manga series Berserk.
Monster 5 is a nod to the bovine spongiform encephalopathy (commonly known as mad cow disease).
Monster 6's appearance, chase theme, death screen and name all refer to Rebecca Black and her infamous song "Friday".
Unknown Specimen 1 is from the horror game Imscared.
Unknown Specimen 2 is a nod to the fangames of the popular horror game Five Nights at Freddy's.
Unknown Specimen 4 is a nod to various Eskimo legends and folktales (such as the Fox Woman).
Unknown Specimen 5 is a nod to the cancelled short horror game P.T.
The secret CAT-DOS entry "Mattress Man" is a reference to a Garry's Mod horror map called "Shadows Chapter 3" made by Akuma Kira, in which the entity appears. It is mentioned that the "Mattress Man" is actually just a Fast Zombie with a box welded to it.
The secret CAT-DOS entry "Lines" is a reference to Space Blaster, a previous horror game made by the developers, which SJSM took some inspiration from.
Events and Rooms
One of the randomly-occurring notes mentions that its writer thinks that picking up too many notes will summon a "tall man character". This is either a reference to the Slender Man, or a reference to Trilby's Notes, the third in a series of freeware horror games, and the first one containing a hostile character known as the Tall Man.
The Final Boss` fireball attack may be a reference to the Dead Man`s Volley, an attack used by the main villain of the Legend of Zelda series, Ganondorf.
A Resident Evil style door animation plays when exiting an "elevator" room.
Rarely, a room with a chair, table, fan and phone can be found. After a few moments in the room, an unnamed person will talk, saying "Hello" in different tones, and on occasion, telling the player not to look directly at the fan. This is a reference to the Five Nights at Freddy's series.
There is a creepy drawing of a character named "Kyubey" from "Puella Magi Madoka Magica" located in one of the classrooms from Room 165.
In Room 614, inside the ventilation, a weird looking monster can be found behind the bars. Sprinting towards the second set of bars inside the vents causes it to run away.
Alternate select screens
When launching the game, there is a small chance that the title will display as "Spooky's Sandcastle of LAND SHARKS", "Spooker's Homecooked BBQ" or a set of distorted teeth.
When encountering the brainframe room after 900 rooms, getting close to the brain will reveal a secret passcode for the final arcade machine in the minigame room.
In Spooky's Jump Scare Mansion HD Renovation, if the player hits the brain jar with the axe, it will crack, and hitting it again will cause it to leak. After a while, the brain will come out of the jar and rush at the player, killing them in one hit. The brain will slow the player down, maing it impossible to outrun it.
- The Brain is one of the few enemies which can kill the player in one hit, after Specimen 9, Specimen 7, Specimen 12, Monster 6 and Unknown Specimen 1 (in the secret second chase).
- The Brain acts very similar to Monster 6 in the DLC, as both enemies are Easter Eggs, both enemies will attack if the player does a certain action and both enemies will kill the player in one hit.