This game OWNS! I was soo impressed by this game, just everything about it. I mean it was made by Epic games, and to tell the truth, Unreal Tournament wasn't too great (at least in my opinion).
NOTE: I'm going to compare alot if this to Halo
-The roadie run and cover system is extremely intricate, yet simple. Much more to it then just pointing the left joystick in any direction. Beats t he crap out of PDZ when cover just seem so...limited.
-The Locust are a much more formidable (and intimidating) foe than the Covenant in Halo. As the lead designer put it in the manual, "Who are you fighting and why do you care?"
-SOUND FX, no game before this have I seen such flawless use of it: from a badly timed active reload, incoming grenade, or calling for assistance, the sound makes a HUGE addition to the game, (not like the "Demon!" or "You are no warrior!", which are just pointless sounds). The music is pretty good too.
-Cinematics, okay in Halo the only thing that really stood out to me in the movies were that they were the same graphic engine as the game (not like SC or the FFs). The movies put chills in me (the factory flashbacks with the Wretchs or the first appearance of the RAAM and Beserker.) The camera angles and flashing lights really make the movies shine and catch your attention.
-Visuals...when I first played this, the graphics were so good I thought my eyes were going to fall out. But after a couple of hours, my eyes felt fine. Graphics...can't really explain them, watch some vids or something.
Overall, this game was just astounding. The enemies are kick-ass and people actually don't mind being them (ahem...Elites in Halo 2). The weapons are a bit similar...but whatever...The life system is better than Halo (in my opinion), that red Gears icon in the middle of the screen is much more scary than the blinking shield indicator. The reviving thing is amazing as well, no more run-and-gun and then die-wait-respawn. And NOTHING cheers me up more than chainsawing a Drones face off...