Ok i copied all this info from the Neogaf thread about Reach concerning new info from the latest GI magazine.
Settings/Locations
* "Darker tone overall" - "Things aren't as bright. But we're not going for that desaturated modern war movie vide either"
* Huge scale combat, new push on big battles
* New perspective. removed sweeping camera shots replaced by cinematic tone, which evokes up close and personal war journalism
Ie, airborne, shot - a ship is filming it from above, ground shots bump and jar like being held in the hands of a runner
* Grittier cinematic sensibility extends to encompass wider character and plot development
* Rugged and harsh wilderness filled with towering mountains and weather beaten forests
* Not a retelling of Fall of Reach
* "We definitely want to take a more serious approach to the franchise"
* "We wanted to delve a little deeper into our characters themselves ... That they're not perfect - they're susceptible to damage."
* "We're bringing some of those things back that encouraged a little more exploration, like wondering where that health pack is"
* Set days before invasion of Reach with an advance invasion force and continues up to full blown invasion
* Noble team investigates trouble on Reach, rebel human Insurrectionists suspected
* Reach features various natural and artificial environments, ambient life and cultures
* Reach transforms from living planet through stages of it's death throes and ultimate fall
* Secret ONI hard sites, early colonist homes, gritty industrial locations, sprawling vistas featured
Gameplay
* Health system more similar to Halo:CE than Halo 3:ODST
* Assassinations, melee executions on unaware enemies from behind
* Armour abilities, seeming replace equipment, each Spartan can only carry one at a time, governed by a recharging meter. Sprint and Active Camo confirmed.
Multiplayer
* Feature parity with Halo 3
Weapons/Vehicles
* New DMR (Designated Marksman Rifle), single shot, fits between Sniper and BR, medium to long range but still deadly at short
* New Needler Rifle, mid range headshot weapon, combining needler (following) mechanics with more accuracy and flexibility, three hits combine and explode
* Returning weapons include AR, Plasma Pistol, Sword, Needler, Shotgun, Sniper Rifle
* Spike and Flame grenades removed
* New air vehicle, the Falcon (featured in trailer)
* Warthogs return
* Civilian vehicles usable
* Spirits, Covenant dropships featured in Halo:CE return
Enemies
* "We're taking a meaner approach to the Covenant overall."
* Covenant enemies now speak their own languages, in low guttural voices (Shakespearian fans am disappoint)
* New enemy, Skirmishers, cunning enemies that hunt in packs, visually related to Jackals
* Elites are back in command of Covenant forces
Engine Tech
* Refined approach to distance and detail
* Allows dramatically expanded number of enemies, light sources and other details
* Described as "imposter tech"
* Level of Detail (LOD) system allows building of bigger and more populated spaces for exploration
* Distant objects are rendered at low poly with cheaper shaders, ie "imposters"
* Imposter look great at distance and detail increases the closer you get to them
* Less chance of pop-up and stippling as environmental geometry, plants, buildings, enemies or anything else can be placed into the visual field at the same extreme distances without profound hit to system performance
* At extreme close range items can be rendered with incredible detail, ie, a wall was shown from inches away with tiny rivet features in the metal popped on the screen with perfect clarity
* Imposter system indirectly frees up memory which can be devoted to other technical aspects
* Lighting being one of those aspects
* From Halo 3's 3 or 4 light sources, Reach's engine presents 20 to 40 dynamic lights at the same time
* Weapon effects benefit greatly from the improved lighting, ie Plasma bolts moving across the screen with their own independent light source, casting colour and shadow across the environment
* More improved lighting examples, a Warthog gun firing at a wall with hundred of real sparks flying from the stone, the particles interact not just with the wall geometry, but with it's normal map additionally, the particles scatter down onto a nearby vehicle and react with its curves and lines, the sparks bounce and flow along the tiny textured surface
* New weather system bringing rain to many missions, adding to the atmosphere
* The sky is no longer a sky-box like past Halo games, it's a true space in the overall environment, ie a ship descends from orbit and towards you, you can watch it make the full descent as a real object would fall
* Motion capture heavily implemented, a majority of the cut-scenes based on captured actions
* On-screen characters exhibit an animation technique known as variable gait blending, when a character changes speed, ie walking to running and vice versa, the animation of walking blends seamlessly into running and then sprinting, also, when turning on a pivot, players no longer stay still and magically turn in a circle, they realistically move around the pivot with their bodies and lifting their feet in reaction
* Bungie hired company Image Metrics to aid with human faces, which now appear dramatically more lifelike than Halo's traditional potato faces
Lone Wolf/Main Character
* Impressive list of combat record accomplishments
* Strikes out more often than his superiors might like
* "Background shrouded in some pretty dark secrets"
Noble Team
* Spartan III's, except Jorge-052 (II)
* Keep surviving suicide missions
* When one members goes MIA, another is brought in
* Carter-259 leader, Kat-320 second in command, both original team veterans and share a bond (ie they have never been replaced in Noble Team)
* Jorge-052 is the only Spartan II on the team. the bigger, bulkier heavy weapons specialist and has survived countless battles
* Emile-239, skull helmet wearing silent type, let's his actions speak for him
* Jun-266, thoughtful, taciturn sniping soldier