I'm loving DOOM 3 right now! I remember when I used to play DOOM many years ago. There's been a few bits in this game where it's made me jump several times, and especially when I can hear the spiders but can't see them haha! I'm currently on the Monorail level so I think i'm about halfway through the game now.

Been doing a walkthrough for it if anyone is interested.
It's not split in to chapters i'm afraid, just parts, but hopefully some people will find it helpful.

i can't wait to continue playing the rest of it.

You're better off doing one for the original PC release.