Microsoft let me play a finished copy of Halo Reach on one of their Xbox 360s today. They even let me save my progress to my Gamertag.* I can talk about two missions, but I don't want to spoil things.
But, sorry… I can only be so vague. I will give away nothing of the plot but mention some skirmishes and some new weapons, abilities and vehicles. Deal with it, mighty Spartans. You're about to be bombarded with Halo Reach details from the Xbox 360's marketing machine anyway.
Beyond the opening missions, I can tell you what I experienced with my lady Spartan, the fierce fighter Noble 6, my Halo Reach heroine. (You can play as a male Noble 6, but that's so Master Chief. I've done that.)
The Deadly Night
The first mission Microsoft's people will let me discuss is Nightfall, which is the third or fourth mission in the game, depending on how you're counting. We're on the planet Reach, which, having played all the games but not read any of the novels, I will bravely say feels like any other piece of Halo game terrain. We've got orange rocky places to climb that could be in the American southwest. We've got beautiful valleys and vistas, huge skies and building complexes made of metal. Nightfall occurs at night and begins with Noble 6 armed with a sniper rifle and allied with one of the several Spartans on your team for this game. Ostensibly, the mission is stealth. I know this because my first enemy in the mission had his back to me. A character in the game whispered a suggestion that I knock him out. After that, you're soon in the thick of classic Halo combat.
More at http://kotaku.com/5621058/a-day-with...hed-halo-reach