Halo E3 2000 trailer

Halo E3 2000 Announcement Trailer DLPA9KxgsNE

At E3 2000 an early trailer for Halo: Combat Evolved was shown. It depicted events not in the final game.

Some Elites are depicted on patrol, and are sniped by the Master Chief who has a different and more robotic voice. He then claims that a landing zone is clear, and a Pelican dropship flies in, putting down Marines and a Warthog. They split into two teams, headed for the same destination. As they travel across Halo, they encounter native wildlife not in the final game, resembling Dinosaurs. They take out a Covenant Wraith and proceed into an underground chamber where they are soon ambushed and massacred by more Elites, the only Covenant alien featured in the Trailer. One Elite in Particular is depicted wielding an energy sword in one hand and a large Energy Shield on his other arm. It is possible that it was shrunken and transferred over to the Jackals in the Final game. Near the end of a trailer a Marine detonates a grenade to take out some enemies before they can murder him. An early version of the Spectre is also seen in the background.

Eventually only one Marine is left and is saved by the Master Chief, who then impales an Elite with an Energy Sword.

Noticeable Differences
Sound effects for the weapons differ, as do the visual effects used during their firing. They make longer laser-like streaks and noises instead of the short plasma blasts.

Halo is depicted as having an assortment of native wildlife.

The Banshees depicted have tail flaps that act as a rudder for aerial steering.

The Assault Rifle used by the Marines appears to have a wood finish on various parts.

The Marines are depicted to be much more efficient in Combat than the Final game would prove. Their armor and color of uniform differs slightly, and their "scouter" eyepiece is red, instead of green.

The Elite's design is slightly different in some scenes, where it has a lower jaw instead of the four mandibles.

There is an early version of what appears to be the Spectre. It seemingly was meant to be in the game also, but didn't make the cut until Halo 2 came out. This is probably where the Shade turret came from, as there is one planted on top of the Spectre.

The Master Chief uses an Energy Sword, which he isn't able to do until Halo 2, he has a different voice, and a radio antenna on his shoulder. When he is hit by enemy fire, his shields flicker blue instead of yellow.

The Elites don't seem to have any shields like they do in the final game.

The Elites also sound very different, and bear a noticeable resemblance to the noises made by the Flood in the final version

The marines' warthog is armed with some kind of light artillery piece capable of knocking out a wraith in one shot, rather than the LAAG in the the shipping version.

The Trailer is little more than 9 minutes long, and a good watch. See Links below for a Download.