* ''Marathon'' has several levels named after quotes from ''WesternAnimation/BeavisAndButthead'', such as the first level with lava being called "FIRE! FIRE! FIRE! FIRE! FIRE!," or the level with the first hidden flamethrower called "Smells like Napalm, tastes like Chicken!" "The Hard Stuff Rules..." seems to be another Beavis and Butthead reference, and "Couch Fishing" is another.
* ''Marathon'' level names are loaded with shout-outs... and bad Pfhor puns. Sometimes both at once.
** "[[Film/ApocalypseNow Smells Like Napalm]], Tastes Like Chicken"
** "[[Film/ForYourEyesOnly Pfhor Your Eyes Only]]"
** "MarsNeedsWomen"
** "[[Literature/WheresWally Waldo World Arena]]"
** "[[Franchise/StarWars You Don't Need to See My ID]]"
** "[[Film/BillAndTedsExcellentAdventure Waterloo Waterpark]]"
** "[[{{Theatre/Hamlet}} The Slings and Arrows of Outrageous Fortune]]"
** "WhatAboutBob?"
** "[[Literature/AliceInWonderland Curiouser and Curiouser]]"
** "If I Had a Rocket Launcher, I'd Make Somebody Pay" (Bruce Cockburn, ''[[ProtestSong If I Had a Rocket Launcher]]'')
** "[[Film/MillersCrossing Where the Twist Flops]]"
** "Feel the Noise" (a reference to a song by Slade, CoveredUp by Music/QuietRiot)
** "[[Literature/{{Foundation}} All Roads Lead to Sol...]]"
** "[[Film/MadMax Thunderdome]]"
** "[[Film/TheEmpireStrikesBack No Disintegrations]]"
** "[[Film/PulpFiction OK, Honeybunny]]"
** "[[Film/ReturnOfTheJedi Lack of Vision]]"
** "[[{{Theatre/Hamlet}} Poor Yorick]]"
** "[[Literature/DoAndroidsDreamOfElectricSheep Electric Sheep One]]"
** "[[Franchise/StarTrek Where Some Rarely Go]]"
** "[[Film/BladeRunner Electric Sheep Two]]"
** "[[Film/ApocalypseNow Naw Man He's Close]]"
** "[[Literature/TheHobbit Foe Hammer]]"
** "[[Literature/TheRimeOfTheAncientMariner One thousand thousand slimy things]]"
** "[[Film/IndianaJonesAndTheLastCrusade A Converted Church in Venice, Italy]]"
** "[[Franchise/CthulhuMythos Strange Aeons]]"
** "[[Film/MadMax Beyond Thunderdome]]"
** "Music/HouseOfPain"
** "[[Music/ThePolice King of Pain]]"
** "[[Music/TheFugees 'Fugee Camp]]"
* In "Rise Robot Rise", Tycho says, "Don't sweat the details, little monkey. Leave the strategizing to those of us with planet-sized brains", a clear reference to ''Literature/TheHitchhikersGuideToTheGalaxy'', in which Marvin complained, "Here I am, brain the size of a planet, and they ask me to take you to the bridge. Call that job satisfaction? 'Cos I don't".
* The "I am a hero" terminal is generally regarded to be a ShoutOut to Creator/MichaelMoorcock's Eternal Champion.