Cut Halo 2 levels

During the development of Halo 2, several levels were cut during development.

alphagasgiant
"Go to Alpha Halo, find the Heretics and destroy their base"

This level is present on the September 2003 build of Halo 2. It appears to be an early version of The Arbiter or The Oracle, set in the Threshold gas mines. Upon spawning in, the player is in a dark room with several Special Operations Sangheili. The SpecOps Elites have no weapons and simply walk forward. Falling out of the level can reveal the gas mine geometry. The level has an extremely low frame rate.

alphamoon
"Assault the occupied control room and find the oracle"

A cut campaign level on the September 2003 build of Halo 2. This level seems to have the same story goal as the level The Oracle from the final game, involving the Arbiter securing 343 Guilty Spark for the Covenant. Unlike The Oracle, this level would be set in a heretic camp on Threshold's moon, Basis - the setting of the multiplayer map Burial Mounds.

Covenant Ship
This level was to take place immediately following Cairo Station. The level would have seen the player, as John-117, board a Covenant with a team of ODSTs, serving as the main introduction for Miranda Keyes. After opening the airlock of the Cairo Station's docking bay, the player would be blasted toward the Covenant ship and board it instead of destroying it with the bomb as seen in the final game. This level would have involved infiltrating the Covenant ship, taking on and killing its crew and eventually stealing a Wraith and end up destroying the ship by bombarding its power core with the Wraith's mortar.

As mentioned by Joseph Staten, Miranda Keyes and her ODSTs would have also been onboard the ship in order to help you and may have played a big role in the eventual outcome. This level however was cut due to time constraints and replaced by a cinematic that created "just as much work" for Bungie Employees.

deltacontrolroom
"Start the revolution and recover the sacred icon"

Seemingly an early version of the final level The Great Journey present in the September 2003 build. This level is unlit and untextured, spawning the player by the "Scarab dock" structure from the final level. On spawning, a Banshee, a Phantom and a Wraith attack the player. The vehicles cannot be boarded.

deltatemple
"Warp to Delta Halo and assassinate the Prophet"

Present on the September 2003 build of Halo 2, this level has several Forerunner temples reminiscent of the levels Delta Halo and Regret. The player spawns with an SMG and a sniper rifle, but no enemies populate the space. The art in this level was likely created by Paul Russel. When playing, the level has a low framerate.

Curiously, when entering the multiplayer lobby of this build, deltatemple is available for play as a multiplayer map. In the menu, the level's preview images are those of early builds of the final level Ascension.

earthcity
"Pursue the Covenant through a human city"

An early version of the level Metropolis in the September 2003 build, bearing heavy visual resemblance to the Halo 2 E3 demo. A large section of the city is modelled, with Wraiths attacking the player.

Forerunner Tank
The level named Forerunner Tank was only revealed on the Halo 2 cutscene commentary contained in the Halo 3 Legendary Edition's Halo 2 cinematics commentary. The purpose of the level was to tie in plot between the end of the level Regret and the cutscene after the end of the level Quarantine Zone. The level was said to be placed after the cutscene in Quarantine Zone where the Arbiter is pushed down the index chamber by Tartarus and before the cutscene where the Arbiter meets the Master Chief and talks to the Gravemind. This level was supposed to be the Gravemind's introduction; in the level, the Gravemind's tentacles were going to slam down all around the player, and move behind doors like racing freight trains.

The level would have described the Master Chief's adventure through the bowels of Delta Halo before his eventual capture by the Gravemind; the "Forerunner Tank" providing the namesake of the level was only described as something "... awesome, that blows things up, glows a lot from little windows and moves real fast." When asked why he wanted the Forerunner Tank in the game, Jason Jones' response was, "Awesomeness would ensue". The level's replacement was the short cutscene at the end of Regret; the level's removal resulted in the long series of different cutscenes between Quarantine Zone and Gravemind.

forerunnership
In-house name for the level High Charity, this level was to have Halo 2 ' s Warthog run but was ultimately cut for time. The level geometry remains mostly intact in the final Halo 2 game, and through modding can be rendered playable again.

sentinelhq
"Breach the sentinel quarantine"

A level present on the September 2003 build of Halo 2. The level was not launched in the Halo 2 E3 demo stream, leaving information about the level minimal aside from its name and description. Presumably, this level would take place around the levels Sacred Icon or Quarantine Zone.

Anchor Point
A multiplayer level tested during development. Anchor Point was to be a predominantly 2v2 map, designed for aerial Banshee dogfights. The map was revealed by Vic DeLeon on Twitter, and was scrapped as it purportedly "played like crap". The level files still exist at 343 Industries, with Jeff Easterling having played it as recently as November 2019.

Development and testing levels
These levels were created for the testing of various game features, and were never intended for release.

AI_test
"Test the AI!"

AI_test is a testing environment on the September 2003 build of Halo 2. In the build played by Brian Jarrard and Frank O'Connor, this level simply loaded with two Hunters and a non-flyable Banshee in a small room. The room has some corridors around the outside, and some textures more closely resembling those of the final game - though some objects simply display UV checker textures.