I've heard that while the latest version/remake of D00M has outstanding graphics, it lacks something that the original D00M has.
Either way, I have read that you can access the 'original' D00M levels by completing certain tasks.
The question is, are the 'original' levels with the upgraded graphics from the new game or not?
*thinks that maybe he should ask Gooooogle instead.
EDIT: Asked Google.
It appears the you get play the original levels as mentioned, however, the only 'original' thing is the maps are from the first game and wall/roof/floor textures are low rez.
From what I have read, the monsters are replaced by ones from D00M 4 (2016) along with the weapons.
Still, not a bad effort really. Will have to see if I can get my hands on a copy ones of these days.
Tomorrow in celebration of our favorite scary holiday I will be playing Outlast 1 at 20:00 UTC. Anyone who wants to join me are free to do so. ^_^ I'll likely only play a part of Outlast, but I'll play enough to make me twitchy and paranoid as hell.