Easter eggs
The game has many Easter eggs, references, and homages to various video games, movies, anime and other media content. Warning: spoilers below.
- The Hitchhiker's Guide to the Cataclysm - Reference to a real book named The Hitchhiker's Guide to the Galaxy by Douglas Adams. Description of the ingame book mentions the "DON'T PANIC" phrase, which is a phrase located on the cover of fictional book with the same name The Hitchhiker's Guide to the Galaxy. There is also the profession Hitchhiker. The character starts with a house coat, slippers, towel, and this book, which is a reference to the book's protagonist Arthur Dent, who narrowly escapes the destruction of Earth in his bathrobe and slippers.
- Permanent marker - Description states that "writing "Elbereth" probably won't help you." This is a reference to the NetHack roguelike, in which you can engrave this word on a tile, and this will prevent monsters from attacking characters while they are standing on that tile.
- Porkpie hat - The description mentions that it is ...still common among [...] people named Heisenberg.. This is a reference to the TV series Breaking Bad, in which Heisenberg is a name the protagonist Walter White has taken for himself to mask his identity. Also, there is a Mobile Meth Lab vehicle in which you can find this hat. The vehicle itself is a reference to Walter cooking meth out of a similar vehicle in the show.
- Resident Evil - laboratories have a half-flooded room with a fire axe in it.
- Human snail - Reference to the Uzumaki manga by Junji Ito.
- Spoon - The description says "Do not try to bend the spoon. That is impossible.", which is a phrase from movie Matrix.
- RM451 Flamethrower - Reference to the book Fahrenheit 451 by Ray Bradbury.
- Island prison The location has a graffiti hidden on the east side of the isle. The text of the graffiti is "Dufresne was here" which is a reference to The Shawshank Redemption movie's protagonist Andy Dufresne who was sentenced to life in prison.
- Two-tile motel location - Reference to the The Walking Dead video game. Its layout, RV, and a graffiti with text "Big half-erased pink X" copies one of the locations from the game.
- St. John Dairy Farm - Another reference to the The Walking Dead video game. It's the cannibal farmhouse featuring the named NPCs of the family members as zombies (Andy the son, and Brenda the mother), Mark (who is a crawling zombie), a Zombie named Danny in a bear trap, and a singular cow named Maybelle. There is also an additional brainless zombie named Larry, hiding in the back of the barn.
- One of the pawn shop locations - Reference to the Pulp Fiction movie. Its layout, loot (in particular, katana, chainsaw, baseball, and hammer), motorcycle near the entry, corpses of Gimp and Maynard, zombified cop Zed, and many other things copy one of locations from the movie.
- One of the survivor notes mentions "...these Global Athletics Games in Harran..." - Reference to the Dying Light video game. Harran is a city in Turkey. The game's events take place in fictional city state of Harran. Global Athletics Game is a fictional sports event which took place in Harran.
- One of the lab notes mentions "...our competitors - he couldn't exactly remember their names, something like "Hole Science" and something related to black mountains..." - Reference to fictional companies Aperture Science and Black Mesa respectively, from the Half-Life and Portal video game series' universe.
- The Thing, and how it spawns from a Friendly Dog, is a reference to both the John Carpenter movie "the thing", which was based on a movie called "The Thing From Another World.", which was based on the novella written by John W. Campbell, Jr. called "Who Goes There?". There even was a mediocre 'pre-sequel' made in 2011, which confusingly is also called 'The Thing'.
- Fallout - A rare city with the same organised layout, the Necropolis is a reference to the Fallout series, the irradiated wanderers found only there are based on the feral ghouls, there is also a vault underneath the Necropolis, which were the fallout shelters in the series.
- Cephalopod mutagen - Injecting this displays a message about it flowing through your veins as "a maze of little twisty passages. All the same"; a reference to a maze in Colossal Cave Adventure, the first ever text adventure game from 1976.
- mininuke - Most likely a reference from the fallout series.