Inventory system like Quake II originally was supposed to be introduced in first Quake, but that idea was dropped off.
Unused commands
Quake contains a command called +use, a leftover from the days of Doom. It is absolutely useless in-game.
Unused graphics
Animations
The Grunt has secret animations of him reloading his Shotgun. John Romero said it was unused because they “most likely” ran out of time. They did not know that Kevin Cloud made it and so they did not use it.
The Ogre has unused animations of him standing and tapping his Grenade Launcher and chainsaw together. This was an one-off animation that id Software saw no use for, so it remained unused.
John Romero wanted the Ogres to laugh and urinate on Ranger’s corpse after they killed him, but they did not have sufficient time to implement this.[1]
The Scrag has special animations of it rising above.
The Knight has secret animations of him kneeling down with his sword held with both hands.
The Death Knight also has unused animations of him standing and swinging his sword overhead with both hands. There are also ones of him standing, and pointing his sword forward with both hands, as if firing something.
Face
The gfx.wad includes an alternative version of Ranger’s face after he acquires a Pentagram of Protection.
Quake was going to include gibbing animations for Ranger’s face, as well as images with his tongue protruding.
Firearms
A weapon flashes on the HUD after it is acquired, but the acquirement animations for the Shotgun are never seen since everybody already commences with one, and the Shotgun has no world model like the other firearms.
Keys
Quake was supposed to contain specific icons for all three types of Keys, but only the Medieval ones remained in use. Nonetheless, two icons for the Runic Keys still exist in the graphics WAD, where they are strangely called INV_NAILS (gold) and INV_ROCKET (silver).
All Keys were supposed to animate in the HUD once they were acquired.
The above graphic includes icons for a rocket backpack, a lettered cube, and a boot. Besides those, there are also frames of animation for the Runes when they would be acquired.
The rocket backpack would let the user hover in the air for about ten seconds. One could jump, activate it, and then float for ten seconds.[2]
The Hellgate Cube was a sentient object that fed off the damage that one did to living beings. The more it was fed, the more it would help the user by shooting evil wisps of smoke into opponents. If one ran around a level too long without killing something, it would go away for a while.[2]
The boots made Ranger run twice that of his running speed for ten seconds.[2]
Screen
There exists a screen that attempted to persuade you into purchasing the full version of Quake. It’s impossible to see this in-game.
Textures
There were alternative forms of the player’s portrait.
The texture map for the Grunt features an unused set of eyes towards the top, and two extra faces on the right.
The one for the Knight contains two unused faces, which resemble those from Qtest. It appears that the right face was used for the Death Knight.
The Ogre originally had two horns on its head, which can both still be seen on the right side.
The Death Knight has a clean spaulder in the center.
The Fiend has a slightly different upper mouth.
Unreleased maps
There are a few maps that did not make it into the final game or the sections of them were repurposed to other maps:
AMLEV13 — not much known about this level, it was supposed to be secret level of Episode 3: The Netherworld.
Unnamed map with Giant Zombie was planned by American McGee to serve as the Boss level in ending of Episode 2 or 3 (probably 3, as American McGee designed most of the levels in third episode), according to Sandy Petersen. [3]
DM7: The Court of Death — a cut Deathmatch level by American McGee that was finished by David Namaksy and released with port of Quake to Nintendo 64. Later, it was added to 2021's Remaster version as DM8.
JRE1M5 — Remake of Classic Doom's E1M5 by John Romero. It was planned to be included in Shareware episode as secret level, a few 1995 screenshots were present in quakepix.zip.
SMED1 — Medieval Castle level by Sandy Petersen. Only trace left is mention in early draft of level layout.
AMMET3 — Metal level by American McGee. Only trace left is mention in early draft of level layout.
AMMECH1 — Metal level by American McGee. Only trace left is mention in early draft of level layout.
AMMECH2 — Metal level by American McGee. Only trace left is mention in early draft of level layout.
AMMET4 — Metal level by American McGee. Only trace left is mention in early draft of level layout.
AMMET5 — Metal level by American McGee. Only trace left is mention in early draft of level layout.
JRBOSS — Boss level by John Romero, might be final end.bsp. Only trace left is mention in early draft of level layout.
END (beta3) — Shub-Niggurath's Pit (Beta3), the level was redone in release version, but used a few ideas from this one.
DM8 - Unreleased prototype of Deathmatch level, containts only one half-finished empty room. Prototype's map source was released in 2006 by John Romero in celebration of Quake's 10th Anniversary.
jrwiz3 screenshot in TrenchBroom editor.
Tim10 screenshot in TrenchBroom editor
Unused level design
E2M6: The Dismal Oubliette originally had a large, watery cavernous area before the spawn point: an actual oubliette. This was removed because the final compiled map was too large to fit onto a floppy disk (presumably for ease of transfer during development). This area was later released as E2M10: Lost Entrance of the Dismal Oubliette,[4] and then included in the 2021 rerelease.
Room with conveyer belt from hip1m3 (?) was cut, but seen in Mission Packs promotional trailer. [5]
Unused sounds
Sounds
Ambient
While many ambient sounds exist in Quake, the Thunder sound effect is never used. Attempting to use it results in an error about the sound not being looped; it cannot function without modifying the code.
Doors
A locked Door was supposed to generate a specific sound effect after its opening. The three sound effects are for the Base Doors, the Medieval ones, and the Runic ones, respectively. (These were implemented in the 2021 rerelease.)
Death Knight
After a Death Knight was hit, he was supposed to grunt. This sound is still precached upon loading their levels.
Shub-Niggurath
Shub-Niggurath possesses two unused sound effects. The first is for when she has detected her nemesis, and the second is for when she is conscious of him. They are precached upon loading her lair, though there is unfortunately no code to play these sound effects.
Unused text
“
"Player" was incinerated by the Chthon
”
Chthon will throw his lavaballs at the player and destroys the player to pieces.
“
"Player" became one with Shub-Niggurath
”
Shub-Niggurath could never do much to harm anybody, and getting destroyed by her will only display a generic obituary.