Much like any video game, the Portal series contains a large amount of unused content that was cut from development due to a series of reasons either given or disclosed. Below is a list of characters and other unique mechanics that were unfortunate enough to be put on the chopping block.
The Crusher was featured in the Portal teaser trailer, but not included in the final game. It is a slow moving panel with spikes that descend from the ceiling when the player is underneath it. The crusher was included in some of the bonus chambers of Portal: Still Alive, and made an updated appearance in Portal 2.
The Walking Turret, also known as the Moving or Mobile Turret, is a Sentry Turret variant cut from Portal. The turret had a personality construct design and the ability to roam through portals and shoot in a way identical to the single directional Sentry Turret that it was replaced with.
Early versions of Portal had Handheld Portal Devices that looked very different from the retail version. One iteration resembled a pistol, while a later version had a strong resemblance to Half-Life 2's Gravity-Gun.
Portal: Still Alive has the same unused content as the original game, with the exception of Crushers, which appear in the bonus chambers. However, Portal: Still Alive also contains some unused or cut content of its own.
Portal: Still Alive contains 14 bonus chambers. However, it appears that a 15th chamber was at one point planned, as an icon for it exists in the files, showing a section of the escape sequence from the original Portal: The Flash Version MapPack. This is further supported by the entrance sign in chamber 14 showing the "cake" light on; this usually indicates the chamber will end in an escape sequence, but chamber 14 doesn't.
No playable 15th chamber exists anywhere in the final game, and it is also not present in the leaked map source files, so what the map looked like outside of this one screenshot is unknown.
In Portal: Still Alive, Pedestal Buttons connected to cube droppers are given a different skin, with red lights on the sides and an image of a skull on top. A matching cube skin exists, but goes unused.
This mechanic was mentioned to allow players to stick to wherever the gel was placed. It was cut from the game when play-testers complained of motion sickness.
In the "scripts" folder of Portal 2, a file called "npc_sounds_android" can be found. The file references sounds that were not shipped with the game, nor does attempting to spawn the npc yield any results. May be a reference to the "Android Hell" GLaDOS has mentioned.
Not much is revealed of the chicken, but concept arts released revealed that a giant chicken may have been a boss for either the prequel to Portal or early stages of Portal 2. Minor evidence of the chicken's leftover files are in the "scripts" folder of Portal 2's directory files.
This mechanic was originally intended to be the primary handheld testing element for a prequel to Portal. The developers very much praised the concept but after the prequel itself received negative feedback from playtesters as they were expecting a sequel with the Portal Gun, the F-Stop project was canceled and it was decided to keep the mechanic disclosed to reserve for another potential game. In 2020, it was revealed to be a camera which could store photographed objects and place them, possibly rescaled.
The "futbol" was a gameplay mechanic that explodes on contact and is the original multiplayer gamemode for Portal 2; which was to carry the device around with portals and to frag other players by dropping these into their presence. The "futbols" also appear to have a dispenser model found in the game's files. The texturing of the "futbols" and its dispensers are similar to the texturing styles of Portal, indicating that this gamemode was cut very early in Portal 2's development. In the game's release, the "futbol" codes have been reused to create the Bombs in the single-player finale.
The Hover Turret may have been intended for Portal 2, and its primary attack is a blue laser beam that brings a similar injury effect as the Thermal Discouragement Beam. No concept arts have been pinpointed to this turret variant, but a screenshot from the The Final Hours of Portal 2 reveals a group of personality cores on a ceiling railing that appear to be "hovering" versions of the Rocket Turret. Further tie in to this can be found in unused textures for the Pneumatic Diversity Vent's passive monitoring screens, showing a personality core with rockets inside to be dubbed as the Hover Turret. It can be spawned in-game, albeit without a proper model and AI.
Spawn code: ent_create npc_hover_turret
The mannequins were used as a testing element for the F-Stop, similar as to how the Turrets were for the Portal Gun. According to the The Final Hours of Portal 2, the mannequins appear to be sentient robots that would later rise against Aperture Science in the prequel to Portal. Along with the prequel and F-Stop mechanic, the dummies were ultimately cut. A deactivated male crash dummy was kept in the release of Portal 2, used as a target for the Turrets' firing range.
Paint Fizzlers are an unused fizzler variant which destroys gel instead of portals. Any gel will splatter on contact with the field, and cubes will be cleaned on contact. It does not affect the player. The particle left in the game (paint_cleanser) appears as a red version of the Portal 1 fizzler field. The entity is used in some maps to prevent players from placing gel on certain surfaces to cheat puzzles.
This type of mechanic was first introduced in a demo of the same name, displaying its abilities to pull objects at a high force. This mechanic is kept as a traveling system around the tube networks. Valve decided this element was not versatile enough to be included in any maps, but it is still fully functional.
An enemy featured in Portal, the Rocket Turret was apparently to make a reappearance in Portal 2, as evidenced by files found the "scripts" folder of Portal 2's directory files. It can be spawned in-game, albeit without a proper model, missing sounds and somewhat broken AI.
Spawn code: ent_create npc_rocket_turret
In the "scripts" folder of Portal 2, a file called "npc_sounds_zombie_aperture" can be found. The file references sounds that were not shipped with the game, nor does attempting to spawn the npc yield any results.
Spite Your Neighbor
Described by Valve writer Erik Wolpaw as "speedball meets Portal", Spite Your Neighbor was going to be a competitive gamemode involving moving a ball from one side of a stage to the other using portals. Other players could use portals as well and "it quickly just devolves into pure chaos", says Wolpaw.
Prior to the the March 3, 2010 patch for Portal the Party Escort Bot was considered to be cut content; it was added back into the game to fulfill its original purpose of "collect[ing] Chell after she escapes the fiery death that GLaDOS had prepared for her."
Early Portal 2 animations reveal that some animations were scrapped from the game due to (possibly) containing creepy properties.