Halo 2 E3 demo

300px|right The Halo 2 E3 Demo was a real-time demonstration of early plans for Halo 2's Outskirts and Metropolis levels.

It was shown at E3 2003, and showed some designs for Halo 2, including ODST's, Battle Rifles, (which were originally going to be single-shot), Dual-Wielding, SMG's, Brutes, the Gauss Warthog, and many other things.

Plot
The Master Chief is en route to a UNSC field command post, turned field hospital, to assist the marines in destroying an artillery cannon and securing the area. The Pelican lands and Master Chief exits with a few ODST's to be introduced to CPL who takes him through the field hospital to where Sergeant Banks is.

The Master Chief proceeds through the camp witnessing the new animations of allied AIs. He then passes through a destroyed building housing a Marine heavy Machine gun team and Sergeant Banks. Both are pinned down by Covenant forces. After Banks delivers his famous line "When I asked for reinforcements, I didn't think they would send a Spartan" he calls in an airstrike on the artillery cannon. A flight of Longsword fighters promptly complies, launching a successful bombing run on the cannon. After the airstrike has occurred Banks gives the player his SMG, an introduction to the new feature of Dual-Wielding. Using his new weapons the Chief clears the area of Covnenant troops before moving over a pile a debris and into a open street.

In the street there is a packed group of about seven Jackals with shields. Upon spotting the Chief they form a phalanx and begin to open fire with their plasma pistols. After a few moments of shooting the group of Jackals are unceremoniously splattered by a pair of Warthogs. One of the Warthogs is the new Gauss Warthog, the driver instructs the Master Chief to man the Gauss Cannon on the back. Upon Chief's entering the turret, Warthogs drive around the street areas which are incidentally quite similar to the streets before the Scarab attack in the Halo 2 level Metropolis. After the Chief destroys a few Shadows and Ghosts, the Warthog is boarded by a Brute who kills the Marines in the passenger and driver seat, an action which ends Master Chiefs ride.

The Master Chief quickly kills the Brute and a few of his comrades before being alerted by Cortana of a fast approaching Ghost. Chief proceeds to board this vehicle by hijacking the Ghost, introducing yet another new Halo 2 feature.

The Chief proceeds to wreck havoc on the Covenant troops in the area before he is instructed by Cortana to escape the area via a tunnel which leads to a bridge. The demo then cuts then changes to a cutscene of two Brutes on Ghosts chasing the Chief through the tunnel. As a sign declaring "Highway access denied" flashes. the automatic doors at the end of the tunnel begin to close. In response to this small crisis Master Chief speeds up, barely making it through the remaining space between the closing doors, although in the process his Ghost crashes, disgorging him upon the ground. However the two pursuing Brutes are not so lucky. The door closes completely before the get to it and a shot from the outside of the tunnel shows the two explosions caused by the fatal crash of the Brutes' Ghosts.

Just after Cortana points out a Covenant ship in the sky, a barrage of glowing drop pods begin to land around the Chief. Elites step out of these Drop Pods and draw their Energy Swords. Chief responds holstering one of his SMGs and charging up a Plasma Grenade. Cortana, noting Chief's action teasingly says "bet you can't stick it" to which the Master Chief responds "You're on." With this the demo ends.

Trivia

 * In the final cutscene Chief uses his right hand to throw the plasma grenade, but in all three games he utilizes his left hand for the purpose of throwing grenades.

Transcript
(Fade in on a massive building complex that dominates the sky)

'''NEW MOMBASA. EAST AFRICAN PROTECTORATE'''

(A Pelican zooms into view. We see the Master Chief)

Cortana: It took two in the nose then dropped into the atmosphere.

Master Chief: Who was first contact?

Sergeant Johnson: 405th out of Diego Garcia.

(Zoom out. We see the Pelican flying over the cloud layer)

Sergeant Johnson: Well, don't expect a big welcome. The Covenant wipe most of them out before they hit the ground.

(The Pelican drops right into the city)

(Fade to white)

(Fade in. We see two marines looking on the LZ. Plasma mortars fly over the air above)

Marine #1: Immediate. Grid Kilo 23 is hot. Recommend mission abort.

Pilot(O.S.): Roger, Recon.

(The Pelican flies overhead)

Pilot: It's your call, Sarge.

Sergeant Johnson: We're going in. Get tactical marines!

(In the back of the Pelican, We see ODST's getting their weapons ready)

Cortana: Covenant ground forces own this city. We'll need to deal with them before we can kill that cruiser.

(The Pelican lands smoothly)

Sergeant Johnson: Pile out. Go! Go! Go!

(The Master Chief hops out)

Sergeant Johnson(O.S.): I'll evac the wounded. Keep me posted, Cortana.

Cortana: Of course, Sergeant.

Marine #2(To the Master Chief): Sir, Corporeal Perez, A- Company. CP's this way.

(Master Chief follows the marine through a field hospital)

Marine Medic: Must be seeing things. Guess the brass didn't give a shit.

Marine Medic #2:  Come on, come on! Stay with me marine!

Marine Medic #3: No tags. Hang two units, Zone A, but he needs an airway.

(The marine stops at a wounded marine)

Marine Medic #4: I'm calling it, 1900.

Marine #2:The Lieutenant got hit as soon as we dropped in.

Cortana: Who's in charge now, Corporal?

Marine #2: Sergeant Banks, Ma'am. He's pinned down out front. C'mon. I'll show you.

(Master Chief follows the Marine yet again. He walks into a building, up the stairs. You hear gunshots)

Marine #3: No! No! Behind that ST. Yeah! Yeah! Yeah! Three more! Coming left.

Marine #4: I'm running low, man!

Marine #5: Parsons! Is it clear?

(Giant explosion)

General Parsons: You tell me!

Marine #5: Friendlies! Movin' out! Coverin' fire! (In the background, an artillery cannon fires a plasma mortar, which fires out overhead. The Master Chief moves along)

Marine #6(O.S.): Grunts, down low.

Sergeant Banks: When I asked for reinforcements, I didn't think they'd send a Spartan.

(The artillery cannon fires another mortar. This time, it hits a nearby building, destroying part of it and causing debris to fall)

Sergeant Banks: We gotta take that thing out. Cover me!

(Sergeant Banks walks over to a dead marine, and takes out his radio)

Sergeant Banks(O.S): Tech Aids H.Q. This is Sergeant Banks. I got a hostile Artillery 200 metres east over my position. Bring smoke, over.

ODST(O.S.): Hostiles right. (The Master Chief continues to fight, with the Artillery Cannon still intact) Sergeant Banks(O.S.): Dammit H.Q. Is anybody on this thing!?

Major Easley(O.S.): Sergeant, this is Major Easley. Hang tight. We're inbound.

(Overhead, two longswords approach the Artillery Cannon, and destroy it, the continue on)

Major Easley(O.S.): Airtight delivery ordnance on target.

Sergeant Banks(o.s): Dead on major! Target neutralized!

Sergeant Banks(to Master Chief): Take my weapon, you'll need it.(He gives the Master Chief two SMG's)

(Master Chief jumps off the balcony, and into further battle. Later, he goes into the damaged building, where more Jackals appear)

Marine #7(O.S.): Frag and clear. Clear out.

(Later, The Chief exits the building and sees a group of jackals, which get run over by a Gauss Warthog)

Marine #8: Could use you on the gunner. We got your back.

(The Chief enters the gunner. A Shadow passes by, and he destroys it)

Marine #9: Thats the way. Yeah!

(The warthog goes along. Then, 2 ghosts appear)

Marine #8: That better buff out.

Marine #9: Ghosts! Making break for it. Quick!

Marine #8: Don't worry. I got'em

Marine #9: Do you wanna let me to drive?

(More ghosts arrive)

Marine #9 That's one!

Marine #9 That's two! C'mon! Whose got more?

(A Phantom flies overhead)

Cortana: A Phantom!

Marine #8: Hang on!

(A second Phantom comes)

Cortana: Brutes!

Cortana: Look out!

(A Brute drops in from the Phantom. He kills both marines, then knocks out the Chief, and the Warthog crashes into the wall. The Chief kills the Brute)

Cortana: Ghosts! To your right.

(A Ghost approaches)

Cortana Wait for it...

(Master Chief hijacks the enemy Ghost)

Cortana: Nice!

Cortana: The marines won't stand a chance if those Phantoms double back. See if you can draw them off.

(The Chief escapes)

(Fade to white)

(Cutscene)

(The Ghost zooms off, and the camera follows it. Behind it, a Phantom approaches, followed by a ghost, and another Phantom. The camera zooms in on the Master Chief. He looks back. The first Phantom starts shooting at the Chief with the frontal turret, with another ghost leading the Chief. He narrowly misses the shots of plasma. The phantom shoots at the 'Welcome to New Mombasa' sign to stop the Chief. It ends up falling on the Phantom, and the Phantom flips on it's side and explodes, with the Chief escaping)

Cortana: Chief...

The Master Chief: Hang on!

(The Chief approaches a closing wall in the highway tunnel. He narrowly escapes, and scrapes the road behind him as he slides down the bridge)

(Inside the tunnel, an enemy ghost piloted by a Brute crashes into the fully closed wall, and explodes. There are two explosions on the other side of the wall.)

Cortana: Bingo! There's the cruiser! Now all we need to do... is...

(Several Elite drop pods land around him. He turns around, and another drop pod lands in front of him. An Elite pops out. It activates it's sword. Around it, more Elites activate their swords)

Cortana: Bet'cha can't stick it!

(The Chief activates his plasma grenade)

The Master Chief: You're on! (the Chief throws it)

(The demo ends)

Differences with the final game
The demo had a vastly different storyline from the final game. Much of it was essentially rewritten to change the events.
 * The ODST's are seen using some sort of flashbang Grenade in order to stun the Grunts and Jackals inside a destroyed building.
 * The New Mombasa Orbital Elevator is nowhere to be seen. Instead, a massive building made up of towering spires and complexes dominates New Mombasa's skies.
 * The Pelican Master Chief lands in is not destroyed, instead it lands normally and disperses its troops without issue.
 * The crosshair is in the Halo: Combat Evolved position, in the center of the screen. In addition there is a much larger field of view.
 * Master Chief passes through a field hospital reminiscent of Turf before engaging Covenant ground troops in combat.
 * Sergeant Banks is an injured Marine who gives Master Chief his SMG, introducing the dual wielding feature. He is directing an attack against a Covenant artillery cannon, instead of a Scarab.
 * Sergeant Banks is introduced at the beginning instead of the end of Metropolis
 * Brutes attack Earth side by side with the Elites.
 * The Chief is trying to destroy one of many landed CCS-class Covenant battle cruisers, instead of a single Assault Carrier.
 * The Battle Rifle reloads like an Assault Rifle.
 * In the Pelican there aren't normal Marines, there are ODST's inside it.
 * The Master Chief fires the SMG's at the same time, and he never reloads them.
 * When the Master Chief changes to the Battle Rifle from the SMG's, he doesn't drop the other SMG.
 * The Battle Rifle is semi-auto and has no ammo counter
 * The Shadow's turret shoots green plasma blasts that look like charged plasma pistol shots, not purple shots. Also, it shoots more automatic, it doesn't get faster as it shoots.
 * It is Cortana, not Lord Hood, who outlines the mission (defeat Covenant ground forces and destroy their cruiser, instead of infiltrating their carrier to capture the Prophet of Regret).
 * Only one Pelican, instead of three, heads to New Mombasa. Also the In Amber Clad is not seen.
 * Major Easley does not appear in the final game.
 * The Elites you see are either some sort of stealth elites or some sort of new elite that didn't make the game.
 * The Brute Shot shoots some sort of plasma grenade which flies straight instead of the frag grenade that falls and bounces after a few feet.
 * The Plasma Pistol shoots a larger bolt.
 * Grunts were seen driving the Shadows, as well as Ghosts.
 * The Phantoms have a different appearance and are destructible.
 * The Grunts and Jackals died the same way they did in Halo 1, with an ocean of blood that flies out from their bodies.
 * The Fragmentation Grenades made the same type of explosion like they did in Halo 1, but are much weaker.
 * When a Brute jumped on top of Master Chief's Warthog, he knocked out two Marines instead of just one.
 * The Brutes are weaker than they are in the final game and were easily killed.
 * The Battle Rifle's melee attack shows three different animations at the same time instead of only one at a time--this was the first animation shown by Bungie of their proposed "melee combo" system, which was cut out of the final game due to time constraints.
 * Pete Stacker may have appeared driving a Gauss Warthog like in the final game but is killed by a Brute.
 * When the Chief shoots a Phantom with a Gauss Cannon a green and blue plasma spark appears.
 * The Gauss Cannon has a faster rate of fire.
 * The Prophet of Regret does not lead the Covenant invasion force on Earth.
 * The SMGs have no recoil.
 * The Ghost's plasma cannons fire simultaneously and faster than in Halo 1, but in Halo 2 they fire one after the other.
 * The back of the Phantom is open and the troops disperse like in a pelican
 * There are no Brutes in New Mombasa in the Final Game
 * The Battle Rifle shot only one bullet and 3 while in zoom. In the final game, it shot 3 bullets.