Halo 2

"Earth will never be the same."

- Halo 2 tagline

Halo 2 is a first-person shooter video game developed by Bungie Studios for the Xbox video game console and is forwards-compatible with the Xbox 360. It is the sequel to Halo: Combat Evolved and is the second installment in the Halo trilogy. The game features a newly built graphics engine and the addition of many new gameplay elements. Halo 2 develops the struggle between the United Nations Space Command, Covenant, and the Flood during the Human-Covenant War in the fall of 2552.

The game was also released for the PC, and is one of the most successful and actively played video games for the original Xbox console, with 8.46 million copies sold as of November, 2008. Despite this, the game's online servers, along with all other original Xbox LIVE services, were discontinued on April 15, 2010.

Halo 2 Anniversary, a remastered edition of the game, will be released for the Xbox One as part of Halo: The Master Chief Collection on November 11, 2014, the tenth anniversary of the global release of the original game.

Characters and setting
Halo 2 does not pick up directly after the events of Halo: Combat Evolved, but rather, after the events depicted in the novel Halo: First Strike, taking place in Halo: Combat Evolved with the events explaining Master Chief's return to Earth not featured in any game so far. The story dives deeper into the society of the Covenant, their goals, beliefs, and alliances, as well as continuing Master Chief's story to put an end to the Covenant threat on Earth as well as another Halo. Halo 2 also introduces the Brutes, who were first mentioned in First Strike. They are shown as large, hairy, ape-like beasts; although they do not don energy shields like the Elites, their immense bulk and strength allows them to absorb a large amount of damage before dying.

The game follows a linear series of episodes that differ from Halo: Combat Evolved. The player will play as both the Master Chief and a troubled Covenant Elite known as "the Arbiter".

Plot synopsis
The game begins on High Charity, the mobile capital city of the Covenant. The former Supreme Commander of the Fleet of Particular Justice, Commander Thel 'Vadamee, is being tried before the High Council for his failure to protect Halo. Despite his insistence that the Flood hampered his abilities, the Hierarchs who lead the council, the High Prophets of Truth, Mercy, and Regret, deem him guilty of failing to protect the Sacred Ring. 'Vadamee is then stripped of his rank and branded with the Mark of Shame by Tartarus, the Chieftain of the Brutes.

The story then turns to Earth's Orbital Defense Platform Cairo Station, where Master Chief Petty Officer John-117 receives the new MJOLNIR Mark VI armor from the Master Gunnery Sergeant. Avery Junior Johnson, who recently got promoted to Sergeant Major, arrives to take the Master Chief to an awards ceremony overseen by Fleet Admiral Terrence Hood for the dual purposes of awarding meritorious acts and boosting the morale of the surviving human population and noted as a war hero (John-117 has already received all medals except for the "Prisoner of War" medal). The festivities are soon interrupted by Cortana reporting "15 Covenant Capital Ships holding position just outside the kill zone," signaling the start to the Covenant Siege of Earth. UNSC Marine forces along with John-117 protect the station from the invading Covenant Naval infantry but other stations were destroyed by the Covenant. After sending the bomb that the Covenant had placed on the station back into space (destroying several ships) he landed on the hull of the UNSC frigate, In Amber Clad. The frigate heads to the city of New Mombasa to fight off the Covenant troops, led by the High Prophet of Regret. After the Covenant invasion force is halted by the UNSC defenses, the Prophet of Regret flees Earth with Miranda Keyes, Captain Keyes' daughter, and her detachment in pursuit on the In Amber Clad. The hasty in-atmosphere jump devastates the city of New Mombasa; destroying the Space Elevator and scattering its wreckage for miles around.

The story returns to the disgraced Elite Commander, Thel 'Vadamee, who is given a chance for redemption by the High Prophets of Truth and Mercy by taking up the mantle of Arbiter and the imminent mortality it entails. The new Arbiter becomes the will of the Prophets, seeking redemption by completing the impossible task assigned to him. Thel 'Vadamee is tasked with the assassination of a Heretic Leader, who is disillusioned with the Covenant following the events of Installation 04 up to its destruction. Thel 'Vadamee tracks the Heretic Leader throughout the gas mine (battling the Heretics and the Flood) where the Heretics sought refuge. When Thel 'Vadamee is finally able to face the Heretic Leader, 'Refumee asserts his belief that the Prophets have lied about the Great Journey. Punctuating this with the entry of 343 Guilty Spark, whom both Elites consider to be an Oracle of the Forerunners, the ancient race the Covenant hold as gods. Before Thel 'Vadamee could learn more of the claims, the battle resumes, and the Heretic Leader is killed before any meaningful discourse takes place. Tartarus appears to extract Thel 'Vadamee and Guilty Spark, further preventing him from learning any further information from Spark. He leaves, not knowing what caused the Heretics to betray their sacred oaths to the Covenant.

Turning back to SPARTAN-117's story, Miranda Keyes ship exits slipspace with the Prophet of Regret unaware that he had been followed. To the surprise of the pursuers, they discover that Regret led them to another Halo Ring. Keyes sends ODSTs to capture the Prophet of Regret while In Amber Clad is repaired; John-117 is dropped onto the surface of Installation 05 with ODSTs to remove Regret. In the course of pursuing Regret, John-117 discovers, with the aid of Cortana, that the Prophet intends to personally activate Halo, in the belief that it will propel true believers on the Great Journey. In order to buy time to acquire the Activation Index before the Covenant can, Keyes orders John-117 to kill the Prophet of Regret, a mission he successfully achieves. But before being able to make his escape, High Charity and its escort arrive and attempted to kill John-117 by glassing the area. He survives by jumping into the lake surrounding the structure in which he encountered Regret. Incapacitated from the shock of the Covenant bombardment, John-117 is last seen being dragged into the depths of the lake by tentacles belonging to a sentient creature.

The story now shifts back to Thel 'Vadamee on the High Charity, in orbit around the ring. The Hierarchs had declared Regret's death to be the Elites' failure, and they were removed as the protectors of the Prophets, who bestow the role to the Brutes, causing more tension between the Brutes and Elites who are already at odds with each other. With the new ring discovered, Truth and Mercy inquire Guilty Spark on how to activate it, and dispatch Thel 'Vadamee to recover the Sacred Icon which will light the ring. Making his way through the Quarantine Zone facing scores of Flood and Sentinels on the surface of Installation 05 seeking the Activation Index, Thel 'Vadamee makes his way into the Library and captures the Index along with Keyes and Johnson after they recovered it from its protective housing. Before he can take possession of the Index, Tartarus again intervenes in Thel 'Vadamee's task. After taking the Index into his own personal possession, Tartarus then reveals that the Hierarchs intended for his death to oust the Elites. His treachery revealed, Tartarus knocks Thel 'Vadamee unconscious down a shaft in the Index chamber to the abyss below.

Beneath the Library, John-117 finds himself in the clutches of the Gravemind, the creature that acts as the sentient intelligence of the Flood. Although Thel 'Vadamee had fallen from a great height, he is saved from plunging to his death by the Gravemind's tentacles. It is within the Gravemind's chamber where Thel 'Vadamee and John-117 meet. In addition, the Prophet of Regret is infected and assimilated into its mass. Also introduced is 2401 Penitent Tangent, Monitor of Installation 05. Both characters act as exposition to Thel 'Vadamee, as Regret remains steadfast to his faith, and the Monitor is fully aware of its status as a weapon. Thel 'Vadamee is further led to question his faith by both John-117 and the Gravemind itself, as they both try to convince the Elite that the Covenant's belief on the Halos is a lie, revealing that the Halos destroy life, not save it. This information, as well the information of the imminent genocide of the Elites lead Thel 'Vadamee reluctantly joining John-117 in the mission to stop the ring from being activated. The Gravemind sends both John-117 and Thel 'Vadamee to different locations to help stop the Index from reaching its destination. John-117 was sent to High Charity to retrieve the Index while Thel 'Vadamee was sent to the area where the Control Room of Installation 05 to halt the Covenant from activating the rings.

John-117 then enters the middle of a broadcast by the Prophet of Truth. After escaping assassination, Truth and Mercy flee to the Dreadnought, and formally transfers command of the Covenant Military to the Brutes. John-117 chases him, killing many Covenant troops on the way, witnessing the conflict between the Elites and Brutes. John-117 also saves a group of Marines along the way. Meanwhile, the Flood, under the control of the Gravemind crash into High Charity using the In Amber Clad. When John nearly meets Truth, he finds Mercy being infected by the Flood; the Prophet tells the Spartan that Truth is going to Earth to "finish what we started." In his efforts to reach the Forerunner Dreadnought, he has to fight his way through the Flood and the Covenant. After boarding the Dreadnought through an energy conduit, he leaves Cortana behind, but promises that he will come back for her.

Meanwhile, Thel 'Vadamee is teleported to near Halo's control room. There, he finds many dead Elites, which were, no doubt, killed by the Brutes. With the help of a few deployed Elites, and sympathetic Grunts and Hunters, he fights his way to meet Rtas 'Vadumee, who is surprised to hear that the Brutes murdered the Councilors. Seeing Tartarus land on Halo's control room, the Elites fight their way to a Scarab, where Sergeant Johnson is held. Johnson takes control of the Scarab and forcefully initiates an uneasy alliance between the humans and the Elites. With the combined efforts of Johnson and 'Vadamee, the Scarab breaches the Control Room doors by using the main energy cannon on the Scarab, and 'Vadamee enters the Control Room to confront Tartarus. In the Control Room, he hears the truth of the Halos directly from 343 Guilty Spark. Still blinded by faith, Tartarus forced Miranda Keyes to activate Halo. Many Zealots and Councilors aid 'Vadamee in his final fight against Tartarus, and eventually after a long and tough fight managed to kill him. Once Tartarus is defeated, Miranda grabs the Index just in time to stop Halo from firing. However, 343 Guilty Spark says that this has activated a fail safe protocol, causing the Installation to send a signal to the rest of the Halo Array, putting them on standby for remote activation from the Ark.

The Forerunner Dreadnought arrives at Earth with John-117 onboard. He alerts Admiral Hood of his presence, and tells him that he is "finishing this fight."

In a scene after the credits, it appears that High Charity has been completely taken over by the Flood, as thousands of Flood spores are visible throughout the air, floating along the view. The Gravemind speaks of satisfaction of being free of his "empty grave," and suddenly Cortana appears as a hologram on a pedestal in the room. The Gravemind then states that there are questions that linger in his mind, which Cortana must answer. Cortana replies, "Alright...shoot." The screen then turns black before any question is heard.

Gameplay
One of the biggest alterations to gameplay in Halo 2 is perhaps the ability to dual wield weapons; this tactic allows for twice the firepower at the expense of being unable to throw grenades or melee without dropping the left weapon. In terms of vehicles, all vehicles from the first game remain except the M12A1 Warthog LAAV (rocket warthog) from the PC version and the Spirit dropship. Also, a few new vehicles are introduced. In Halo 2, however, the previously indestructible vehicles can now be destroyed and the player is able to "board" an enemy vehicle by climbing on and knocking the driver out, as well as planting grenades to further damage the vehicle. The same can be done by an enemy to the player when driving.

When playing as the Arbiter, the player's flashlight is replaced with a rechargeable Active Camouflage that lasts for ten seconds, giving the player a preemptive advantage on unsuspecting enemies.

The player can have a variety of allies; if they are playing as the Master Chief, they will be assisted by UNSC Marines, and occasionally ODSTs. However, the Arbiter is joined by Grunts, Jackals, Hunters, and other Elites, allowing for deeper insight into Covenant culture.

Campaign
The campaign consists of 15 levels, of which 14 are playable.
 * 1) The Heretic - For failure such as this, no punishment is too great. (cutscene; unplayable)
 * 2) The Armory - Suit up, prepare for battle. (tutorial)
 * 3) Cairo Station - Defend the station's MAC gun from Covenant boarders.
 * 4) Outskirts - Rally scattered marines, clear hostile contacts from the old-city.
 * 5) Metropolis - Take the bridge, break the Covenant's grip on the city-center.
 * 6) The Arbiter - Infiltrate a Forerunner facility, quell the heresy within.
 * 7) The Oracle - Kill the Heretic Leader. The Prophets' will be done.
 * 8) Delta Halo - A Covenant army stands between you and Regret. Get to work.
 * 9) Regret - You heard the lady. Locate the Prophet, take him down.
 * 10) Sacred Icon - Succeed where others have failed. Lower the shield protecting the Sacred Icon.
 * 11) Quarantine Zone - Parasites, humans - no matter. The Icon must be found.
 * 12) Gravemind - The Prophets have the Index and plan to use it? Over your dead body.
 * 13) Uprising - This is certain: The Brutes shall pay for the blood they have spilled.
 * 14) High Charity - Cortana can handle the Index - stopping Truth is up to you.
 * 15) The Great Journey - Form an unexpected alliance, keep Tartarus from activating the ring.

Default

 * Lockout
 * Ascension
 * Midship
 * Ivory Tower
 * Beaver Creek
 * Burial Mounds
 * Colossus
 * Zanzibar
 * Coagulation
 * Headlong
 * Waterworks
 * Foundation

Bonus Map Pack

 * Containment
 * Warlock

Killtacular Pack

 * Sanctuary
 * Turf

Maptacular Pack

 * Backwash
 * Elongation
 * Gemini
 * Relic
 * Terminal

Blastacular Pack

 * Desolation
 * Tombstone

Appearances
{{Featurelist|secondcolumn=title-5
 * title-1=Characters|
 * UNSC
 * John-117
 * Cortana
 * Avery Johnson
 * Miranda Keyes {{1st}}
 * Terrence Hood
 * Harper {{1st}}
 * Stacker
 * Banks {{1st}}
 * Perez {{1st}}
 * Jones {{1st}}
 * Butkis {{1st}}
 * O'Brien {{1st}}
 * Parsons {{1st}}
 * Walpole {{1st}}
 * Unidentified master gunnery sergeant {{1st}}


 * Covenant
 * Thel 'Vadamee {{1st}}
 * Rtas 'Vadumee {{1st}}
 * Tartarus
 * Prophet of Truth
 * Prophet of Mercy {{1st}}
 * Prophet of Regret {{1st}}
 * Sesa 'Refumee {{1st}}


 * Forerunner constructs
 * 343 Guilty Spark
 * 2401 Penitent Tangent {{1st}}


 * The Flood
 * Gravemind {{1st}}


 * title-2=Species and entities|
 * Flood
 * Flood infection form
 * Flood combat form
 * Flood carrier form
 * Forerunner {{Mo}}
 * Human
 * UNSC Marines
 * Jiralhanae
 * Captain {{1st}}
 * Chieftain
 * Major {{1st}}
 * Minor {{1st}}
 * Honor Guardsman {{1st}}
 * Kig-Yar
 * Major
 * Minor
 * Sniper
 * Lekgolo
 * Mgalekgolo
 * Sangheili
 * Councilor {{1st}}
 * Field Master
 * Honor Guardsman
 * Lights of Sanghelios {{1st}}
 * SpecOps
 * Major
 * Minor
 * Ranger {{1st}}
 * Stealth
 * Ultra {{1st}}
 * Zealot
 * San'Shyuum
 * Unggoy
 * SpecOps
 * Heavy {{1st}}
 * Major
 * Minor
 * Yanme'e {{1st}}
 * Minor {{1st}}
 * Sentinel
 * Constructor {{1st}}
 * Aggressor
 * Enforcer {{1st}}


 * title-3=Organizations|
 * Covenant
 * High Council
 * Sesa 'Refumee's heretic faction {{1st}}
 * United Nations Space Command
 * UNSC Marine Corps
 * A Company {{1st}}
 * UNSC Navy
 * UNSC Home Fleet
 * Naval Special Warfare
 * SPARTAN-II program


 * title-4=Locations|
 * Sol system
 * Earth
 * Mombasa {{1st}}
 * New Mombasa {{1st}}
 * Sector A {{Fm}}
 * Sector B {{1st}}
 * City center {{Fm}}
 * Docks {{Fm}}
 * Section 14 {{1st}}
 * Industrial zone {{1st}}
 * Kilindini {{1st}}
 * Kilindini Park Cultural Center {{1st}}
 * Mombasa Tether {{1st}}
 * New Mombasa 105 East {{1st}}
 * Kilindini Underpass {{1st}}
 * Liwitoni Station {{1st}}
 * Old Mombasa {{1st}}
 * Grid Kilo 23 {{1st}}
 * Hotel Zanzibar {{1st}}
 * Liberty Street {{1st}}
 * Mombasa Quays {{1st}}
 * Sector 0-5 {{1st}}
 * High Charity
 * Tower Districts
 * High Council Chamber {{1st}}
 * Sanctum of the Hierarchs
 * Hanging Gardens {{1st}}
 * Valleys of Tears {{1st}}
 * Mausoleum of the Arbiter {{1st}}
 * Holding chambers {{1st}}
 * Mid Tower {{1st}}
 * Far Tower {{1st}}
 * Lower districts {{1st}}
 * Installation 05 {{1st}}
 * Control Room (Installation 05) {{1st}}
 * Library {{1st}}
 * Index chamber {{1st}}
 * Quarantine Zone {{1st}}
 * Sentinel Wall {{1st}}
 * Temple (Installation 05) {{1st}}
 * Bastion of the Brutes {{1st}}
 * Jiralhanae encampment {{1st}}


 * title-5=Events|
 * Human-Covenant War
 * Battle of Earth {{1st}}
 * Battle of Installation 05 {{1st}}
 * Battle of High Charity {{1st}}
 * Great Schism {{1st}}


 * title-6=Vehicles|

UNSC

 * Usable
 * M12 Warthog LRV
 * M12G1 Warthog
 * M808B Scorpion


 * Unusable
 * D77-TC Pelican
 * D96-TCE Albatross
 * GA-TL1 Longsword
 * Orbital defense platform
 * ODA-142 Cairo
 * ODA-143 Malta
 * ODA-144 Athens
 * Hog
 * Tractor unit
 * Überchassis
 * Single Occupant Exoatmospheric Insertion Vehicle
 * Tractor unit
 * Überchassis
 * Single Occupant Exoatmospheric Insertion Vehicle

Covenant

 * Usable
 * Type-46 Spectre
 * Type-26 Wraith
 * Type-26 Banshee
 * Type-32 Ghost


 * Unusable
 * High Charity
 * Type-31 Seraph
 * Type-29 Shadow
 * Type-47 Scarab
 * Type-52 Phantom
 * Type-28 boarding craft
 * Covenant drop pod
 * Keyship
 * Forerunner Dreadnought
 * Keyship
 * Forerunner Dreadnought


 * title-7=Weapons|

UNSC

 * Usable
 * BR55 battle rifle
 * M6C magnum
 * M7 SMG
 * M9 fragmentation grenade
 * M41 Vulcan
 * M41 rocket launcher
 * M68 Gauss cannon
 * M90 shotgun
 * M247 machine gun
 * SRS99C-S2 AMB sniper rifle
 * Type 14 Magnetic/Anti-Tank Mine

Covenant

 * Usable
 * Type-1 plasma grenade
 * Type-1 energy sword
 * Type-25 plasma pistol
 * Type-25 plasma rifle
 * Type-25 Brute plasma rifle
 * Type-25 Brute Shot
 * Type-33 Needler
 * Type-33 fuel rod gun
 * Type-50 particle beam rifle
 * Type-51 carbine
 * Type-42 plasma cannon
 * Type-27 Shade
 * Scarab Gun Easter Egg


 * Unusable
 * Covenant artillery
 * Antimatter charge
 * Energy stave
 * Fist of Rukt

Forerunner

 * Usable
 * Sentinel beam


 * Unusable
 * Pulse beam
 * Enforcer missile launcher

}}
 * title-8=Equipment and technology|
 * MJOLNIR Powered Assault Armor
 * Mark VI
 * Active camouflage
 * Covenant communication node
 * Forerunner power core
 * Forerunner energy core
 * Forerunner gas canister
 * Holotank
 * Portable holo-pedestal
 * Holo-drone
 * Camera drone
 * UNSC fusion core
 * Methane recharge station
 * Resupply canister
 * Deployable lookout tower
 * Covenant roadblock
 * Stationary shield generator
 * Gravity conveyor
 * Sentinel manufacturing facility

Audio
A total of 21,090 lines of dialogue was recorded.

Matchmaking
Unlike its predecessor, Halo 2 allowed players to compete with each other over the Xbox Live online service, in addition to the originals support for split-screen and System Link multiplayer. Halo 2's Xbox Live mode offered a unique approach to online gaming that is intended to alleviate some of the problems that have plagued online first-person shooters in the past. Traditionally, one player sets his or her computer or console up as a game server (or host), specifying the game type and map and configuring other settings. The game software then used a service like Xbox Live or GameSpy to advertise the game to the world at large; other players choose which game to join based upon criteria such as the map and game options each host is offering as well as the ping times they are able to receive.

In Halo 2, Xbox Live players do not choose to host games, and they do not get to specify individual maps and options to search for. Instead, players sign up for "playlists" that are geared to different styles of play. For example, the "Rumble Pit" playlist offers a variety of "free-for-all" game types, primarily Slayer or variations there of; "Team Skirmish" offers a number of 4-on-4 team games, which are primarily objective-based games like Capture the Flag; "Big Team Battle Skirmish" is similar to Team Skirmish but allows teams of up to 8 players. Other playlists allow various things such as matches between different clans. The Xbox Live servers create games automatically from the pool of players that have signed up for each playlist, choosing a game type and map automatically and selecting one player to serve as the game's host. Players can create small "parties" with their friends and enter games together as teammates or, in Rumble Pit, adversaries. They can also play custom gametypes like regular multiplayer. Unranked gametypes allow people on the same Xbox console without an Xbox Live account to play with them as "guests". If the Xbox console hosting the game drops out, the Xbox Live service automatically selects a new host from among the remaining players so the game can continue.

Since launching in November 2004, the service has been very popular with gamers. While some players resent the loss of individual control inherent in Halo 2 's approach to online gaming, others feel it provides a significantly improved gaming experience compared to more traditional online first-person shooters. Bungie's servers match players up by skill level, which tends to eliminate the kind of severely imbalanced games that less-skilled players often consider unfair and not enjoyable. The automatic host selection process also eliminates the ability of the host to exert outsize control over the parameters of the game.

Halo 2 players with Microsoft Passport accounts can log on to bungie.net and obtain highly detailed statistics on their performance, including level maps for several hundred of the player's most recent games that indicate graphically where and when the player scored a kill or was killed him or herself.

On April 15, 2010, the Halo 2 multiplayer services, along with all other original Xbox LIVE services, were discontinued. However, some of Halo 2's fans left their Xbox's running after April 15. Xbox LIVE did not boot the approximately 500 people who had signed into Xbox LIVE before the discontinuation of service on April 15. These players continued playing online amongst one another but no new players could sign on. On April 30, 2010 only 12 fans who had managed to keep their Xbox and Xbox LIVE connections stable remained logged into Halo 2 on Xbox Live. Nicknamed the "Noble 12", they continued to play games among themselves. In response, Stephen Toulouse, director of policy and enforcement for Xbox Live, tweeted "To those noble folk keeping halo2 alive: we see you, and we salute you,". These hardcore fans were awarded Halo: Reach Beta keys because of their attempts to keep Halo 2 alive. Over the next 9 days, 10 of the 12 gamers would experience either Xbox malfunctions or Internet malfunctions. Some were reported as logging off voluntarily to play the Halo: Reach Beta they received. Only two people remained online in Halo 2. On May 10, 2010, "Agent Windex" was quoted as saying "I just got kicked off guys. Good Job Apache, you're the last one". Later that day, "Apache N4SIR", the very last person on Halo 2, was booted from Xbox LIVE. This marked the end of Halo 2 on Xbox LIVE and the end of the originial Xbox LIVE.

Halo 2: Original Soundtrack
There are two volumes of the Halo 2 soundtrack, one released alongside the game, and the other released in Early 2006. You can usually find them at any retail store that sells music or games, or Ebay.

i love bees
During the summer of 2004, the website ilovebees.com was used as a publicity site for Halo 2, with the site being pointed to by adverts for the game during movie trailers. Ostensibly a beekeeper's personal site, the server appeared to have been taken over by an unstable A.I. whose thoughts were scattered on the site. This alternate reality game acted as a prologue to the story of Halo 2.

Trailers
In 2002, Bungie released the first glimpse of Halo 2 in a pre-rendered CG trailer. The trailer featured the Master Chief in his new MJOLNIR Mark VI armor preparing for battle in a space station. Cortana is also heard and has dialogue with the Chief. It also featured Earth and s in orbit. The UNSC seem to be losing in the battle. The events of this trailer were featured in the final version of Halo 2. Some of the events and dialogue of this trailer was changed to fit the finished storyline of the game. Most of this now appears in the Halo 2 level Cairo Station.

E3 2003
In 2003 at E3, Bungie released footage of a playable in-game demo of the Halo 2 campaign. The demo featured the battle on Earth in the city of New Mombasa. Master Chief, Cortana, Sergeant Johnson, Corporal Perez, Major Easley, and Sergeant Banks were all seen/heard in the demo. The demo showed off new features like Dual-Wielding (the Master Chief could actually keep both his dual-wielded weapons when he switched to his secondary sidearm; this was changed for the final product), Vehicle Damage, and Boarding. Three new vehicles shown were the Gauss Warthog, Shadow, and the Covenant Phantom, which at the time had only one plasma turret on its underside instead of three.

Returning vehicles featured the Ghost, Pelican, Covenant Cruiser, and Longsword Fighters. New weapons the Battle Rifle, SMG, and Brute Shot were also shown, although the final Brute Shot design for Halo 2 was vastly different than what was shown in this trailer. New enemies such as the Brutes were shown in this demo, but as a secondary warrior race by the side of the Elites. The events of this demo were featured in the final version of Halo 2. Some of the events and dialog of this demo was changed to fit the finished storyline of the game, such as the AA Gun becoming a Scarab. Most of this now appears in the Halo 2 level; Metropolis.

E3 2004
In 2004 at E3, Bungie released footage of a playable in game demo of the Halo 2 multiplayer. The demo featured the multiplayer map Zanzibar and displayed playable character models the SPARTAN-II model and the Sangheili model. It also showed off some of the weaponry of the game and some special features. The Battle Rifle, SMG, Needler, Rocket Launcher, and Energy Sword were displayed. The Gauss Warthog and the Ghost also made an appearance. Some features included the lock-on feature of the Rocket Launcher, the Dual-Wielding ability, Explosive Barrels, Ghost's boosting, vehicle boarding, Warthogs horn and Gauss Cannon and Sword Lunging. Afterward, fans were allowed to try out the demo.

Release and reception
Halo 2 was very successful in sales. In company with PlayStation 2's hit of the year, Grand Theft Auto: San Andreas, it was the most sought-after video game among critics and gamers in 2004. Three weeks prior to launch, stores in the U.S. alone had pre-sold 1.5 million copies of the game to consumers. When it launched for the Xbox on the 9th of November, over 7000 video game, toy and electronics stores in the U.S. opened at midnight to welcome fanatical fans. Halo 2 instantly began to prosper. One national retailer sold 8,500 copies of the game in just 11 minutes, and another had sold 200,000 units by daybreak. One single store sold 500 Halo 2 units in three hours, 350 of them being sold between midnight and 1 a.m. Early on the launch day, Microsoft expected Halo 2 to generate more money in 24 hours on store shelves than any game had done before. Moore said “I'm calling a $100 million day on Halo today.” Halo 2 went on to be the success that Microsoft was anticipating, selling approximately 2.4 million copies in North America in 24 hours, generating $125 million. The video game software retailer GameStop sold more than half a million Halo 2 copies in one day. In Australia, where more than 42,000 gamers had pre-ordered the game prior to its release, Halo 2 shattered retail sales records by selling more than 104,000 units in no more than one week after launch, generating nine million dollars and beating the previous record holder by 38,000 copies. In Canada, Halo 2 succeeded in selling 222,000 units in its debut month, making it the biggest premiere month for any game up to Grand Theft Auto IV. Before its release in New Zealand, more than 8000 units of Halo 2 had been pre-sold.

Three weeks after its release, Halo 2 had sold over 5 million copies, making it the second-best selling Xbox game, with approximately 19% of all Xbox owners possessing a copy of Halo 2. The game also had the most successful opening night of any game up until Halo 3, and, later, Grand Theft Auto 4. The game had a generally amazing reception, gaining a 9.7 out of 10 from OXM (10 out of 10 from its Australian counterpart), a 9.8 out of 10 from IGN, a 10 out of 10 from Game Informer, a 9 out of 10 from Play Magazine, a 5 out of 5 from X-Play, and a 9.4 for Xbox from GameSpot. It gained more Game of The Year awards in 2004 than any other game that year. X-Play, in late 2006, included it as #3 in their top 4 greatest shooters of all time (#4 was Resistance, #2 Half-Life 2, and #1 was Gears of War). In early 2007, it made #8 on their top 10 Games of All Time countdown. The game had an average meta-score of 95 out of 100, making it the 3rd most critically acclaimed Xbox game, right behind Halo: Combat Evolved and the Grand Theft Auto Triple Pack. The games multiplayer was held to be one of the best of all time, staying consistently number 1 the most played Xbox Live title from November of 2004 up until November of 2006, when Gears of War released.

Most critics noted that Halo 2 stuck with the formula that made its predecessor successful, and was alternatively praised and faulted for this decision. Edge noted in its review, “It's fitting that we're able to steal a line from the script to sum everything up. No spoilers here, just an epitaph, from the moment Cortana turns to Master Chief and says this: 'It’s not an original plan. But we know it’ll work.'" According to Xbox.com, the game has received more than 38 individual awards. The game's campaign mode has received some criticism for being too short, in addition to some dissatisfaction with the abrupt, cliffhanger ending that sets up the sequel, Halo 3. GameSpot noted that the story switching between the Covenant and Human factions made the plot more intricate, but also distracted the player from Earth's survival and the main point of the game. There is also some criticism of the game's on-the-fly streaming and level of detail adjustment, which can sometimes result in textures loading erroneously and "popping in" when the camera changes in cutscenes. Bungie has stated that this issue had been fixed for Halo 3 and the Windows Vista port.

In an interview with Edge magazine in January 2007, Jamie Greisemer, one of Halo 's design leads, said that the main reason for Halo 2 ' s shortcomings was a lack of "polish" period near the end of the development cycle. Staff member Frank O’Connor admitted the cliffhanger ending was abrupt, noting “we drove off Thelma & Louise style." Nonetheless, in the interview Greisemer promised that they would make Halo 3 a more than worthy successor.

Rereleases

 * 2005 - Rereleased as part of the Halo Triple Pack which included Halo: Combat Evolved, Halo 2, and Halo 2 Multiplayer Map Pack.
 * 2007 - Rereleased as part of the Halo History Pack which included Halo: Combat Evolved, Halo 2, and a sneak peek of Halo 3, and as part of Xbox LIVE's Xbox Originals.

Trivia

 * Originally, there were to be several kinds of Warthogs including an Arctic model (which was included in the Halo 3 DLC multiplayer map Avalanche), a transport vehicle and a small ATV (known as the Mongoose in Halo 3) would make an appearance. These were all cut from the final version of the game. However, in Halo: Custom Edition, fans created the arctic and transport warthogs, as well as the civilian Warthog featured in the multi-player map Headlong. A rocket Warthog was included in Halo PC and the ATV and variations of the Warthog appear in Halo 3.
 * Jason Jones is known for establishing the quote: "Halo 2 is a lot like Halo 1, only it's Halo 1 on fire, going 130 miles per hour through a hospital zone, being chased by helicopters and ninjas. And, the ninjas are all on fire, too." This led to the famous line of inside jokes, patches and t-shirts, user names, and memes of flaming ninjas.
 * A song, known as "Remembrance" at the start up screen, (the unedited version found on the “Halo 2 Original Sound Track Volume 1") just happens to play for exactly 1:17 (John's serial number) or 77 seconds.
 * Halo 2 has been the only game in the series to have the most content either cut from the game entirely or redesigned completely as evidenced in many forms of media. In the Halo 3 Essentials disc featuring the "Director's Commentary" of the cutscenes, three separate levels were discussed as having been proposed but ultimately scrapped due to time constraints: Covenant Ship, Forerunner Tank, and Forerunner Keyship. In the "Making of Halo 2" documentary there was concept art seen regarding a level location The Ark, although the design was later placed into Halo 3 's The Storm as the Portal. The former could have been a part of pre-production for Halo 3. Marty O'Donnell was also quoted in a Bungie Podcast (Episode 13, at 21:00) saying that all the actors had recorded the lines to the original Halo 2 ending and that it still exists today, but he will never show it. The Flood Juggernaut was a character that was modeled and placed in the coding of the game but never had AI programmed or had been placed on any level, similar to the Engineer in Halo: Combat Evolved.
 * In the final days prior to the deactivation of Halo 2's multiplayer, Bungie added new sayings to the Did You Know? section of the lobby including messages of thanks to Halo 2 fans for staying supportive for the half decade that it was active and hints about Halo: Reach's gameplay. Many of these were worded in a humorous manner, though several were outright jokes.
 * Halo 2 has been played for about 100 million hours on Xbox since its release.
 * Players who played this game with his or her current LIVE account before April 14th, 2010 will unlock the Halo 2 Visual Flair in Halo: Reach.
 * A group of Halo 2 players found that they were able to stay in the online multiplayer servers past the April 15th cutoff if they kept their consoles powered on, and they played in this way for 3 and half weeks until power failures and connection issues booted them off.