They are all over the place.
I am checking it out to see if it is something I can play. It's bothered me a bit, but so far I have been suprised. I may be able to keep playing.
A couple things come to mind. It really is a scary freaking game. I had my room lights out, and a monster jumped out from behind the stairs and I literally jumped. I can't tell you the last time a game made me do that. As for the storyline. I'm going to catch hell for this, but I am not that impressed. It reminds me of too many other games, slightly changed. It also reminds me of too many movies I have seen. Ghost of Mars comes to mind. From that standpoint, I don't find it too original. Now, the way they are doing it is very original. The PDA stuff is cool. So, I give them a D for originality, an A for execution, and an A+ for scariness.
::spoiler:: If you are like me and too lazy to figure out all the storage locker codes, here is a site that will provide a lot of information about them. It does have information that could be considered a spoiler.
http://deviantone.com/doom3pda.html If someone finds a site with more specific locker numbers to locker codes, let me know. I would like to offer it as an article for others to find because it has been so difficult for me to find anything that simple through google. ::spoiler::
Also, for those of you who hate switching to the flashlight, here is a duct tape mod that adds the flashlight to you weapon.
http://ducttape.glenmurphy.com/