Bungie's shown Halo: Reach and revealed an impressive new engine that is far and away the best the series has seen.
According to an article in Game Informer magazine, scans of which have popped up on the internet, motion capture is being used for the first time. Image Metrics - the company behind the mesmerising Emily demo - is in charge of facial animation. State changes from walking to running to sprinting should also now look believable, as should pivoting on the ground.
There's a new weather system, and Bungie has made the sky into a real object that ships can descend out of and onto the planet from.
Whereas Halo 3 could handle three or four dynamic light sources on-screen at one time, Halo: Reach can handle 20 to 40. And there are double the amount of enemies on-screen in Halo: Reach, not to mention a greater visual quality both at range and up close.
There are gameplay changes, too. Bungie has brought mechanics in-line with Halo 1, the game Reach is a prequel to. Health bars again appear when shields are drained, and soldiers must find health packs to keep themselves standing. And flame grenades and spike grenades have been removed.
Halo 1 weapons like the sniper rifle, assault rifle and magnum pistol return. But there are also new weapons, such as the Designated Marksman Rifle: a deadly one-shot weapon that's lethal both at range and up close, should you be twitchy enough to make use of it.
On the Covenant side there's a Needle Rifle, described as a mid-range headshot weapon, that blows enemies up after three successful hits. The Covenant's Plasma Pistols, Swords and Needlers return.
Bungie's introducing stealth kills to Halo: Reach, which are context sensitive and performed by holding down a button when reaching an enemy undetected.
Halo 3's equipment power-ups been scrapped and swapped with new armour abilities, and these can be altered for the task at hand. The player swapped from a sprint ability to an active camouflage ability in the preview.
Halo: Reach follows Noble Team, a six-man group of Spartans - mostly Spartan IIIs. These are Carter-259 (the leader), Kat-320 (second in command), Jorge-052 (the only Spartan II), Emile-239 (the skull-painted silent type) and Jun-266 (sniper).
You'll be Noble 6, a fiery yet commended soldier recruited when one of Noble Team falls.
Bungie promises a darker and more emotional tale this time around, and wants to re-establish the Covenant as a threatening, scary foe. A new enemy type, the Skirmishers - cousins of the Jackals - should help, as they'll quickly form groups and attempt to out-manoeuvre you.
Halo: Reach is due out exclusively on Xbox 360 this autumn.