Err, Doom 3 WAS way way way way to dark. Darkness doesn't make a horror game. In this case it ruined it. The total Darkness combined with the lame scripted A.I. ruined it. I know HL2 used some form of scripted A.I. as well but HL2 isn't a horror game. After the first enemy or two you knew the entire game. Because the game plays the same. Something pops out of a wall or under some stairs..over and over...You shoot them, they disenigrate, repeat. The game wasn't scary at all, and it was pitch black. It just ruined it. That and they shiney blah blah that made the game look like it was textured in MSpaint, then taken into PS to add the plastic filter to it. But the crappy looking game doesn't matter as much to me as the crappy gameplay did. They brag about their lighting engine, but the flashlight was bullcrap. If I turn on a very crappy flashlight in my room you can see the ENTIRE ROOM. Not very bright, but you can see it all, and make your way around fine. In Doom 3 the light allowed you to see about 3 feet infront of you! Was that too make my experience more scary? Failed. It just made the game more annoying. System Shock 2 was scary as hell and it wasn't pitch black. Far Cry even managed to make me jump at some parts..I mean come on...
Doom 3. Too dark. Not scary. Overrated. Poop. <-- My 2 cents.
Think while it's still legal.