Dem good old' games, number 2.

[EverBlue]

Oh, and as to the statement about Doom being a wolfenstein mod, that's not true.
While the Wolfenstein 3D prequel spear of destiny was being finished by most of the id staff, a couple members created a new 3d engine that was dubbed the "Doom Engine", and they created Doom around that.

* Height differences (all rooms in Wolfenstein 3D have the same height);
* Non-perpendicular walls (all walls in Wolfenstein 3D run along a rectangular grid);
* Swaying of the weapon (in Wolfenstein 3D the arms stay fixed in front in the screen no matter what the character does), this gives the impression of fluidity while walking or running;
* Full texture mapping of all surfaces (in Wolfenstein 3D, floors and ceilings are not texture mapped);
* Varying light levels (all areas in Wolfenstein 3D are fully lit at the same brightness). While contributing to the game's visual authenticity by allowing effects such as highlights and shadows, this perhaps most importantly added to the game's atmosphere and gameplay; the use of darkness as a means of frightening or confusing the player was an unseen element in games released prior to Doom.

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