Personally, I wasn't too impressed with Doom 3. I mean, yes... nice graphics. Awesome graphics in fact, but the game play got real repetitive and boring after a while. For such a great engine and how they boasted about it, I'd expect a lot better. Still it's just a game and it's alright if you want to kill some time and blast away at some monsters. Like someone else mentioned, there were some things that didn't need to be put into the game, but then again... this isn't a Christian game
I'm pretty sure that Half-Life 2 won't have to try too hard to be a much better game. If it ever comes out.