I agree with the complaints on some parts, but i really think the thing that bothers me most about the game(although I love the gameplay) is that its so much like other games.
Quake 2, Half-Life and eliteforce 2 combined into Doom 3 (minus the Klingons
). What sucks is, they left out the Doom. Personally, I think this game would have made a better Quake 4 than a Doom 3... just my opinion though.
EDIT: Its also a lot like the Resident Evil movie... super advanced research facility goes to hell, zombies take over, military forces have to fight them off...
Despite all this, its still a really fun game that looks great