Geezus.. How many developers have their fingers in this. An Enhanced version (who did this) of Midway's take (code update and modification) of ID Software (the guys and gals who made this.) FPS franchise that was released for the NINTENDO 64?! WTF so instead of just taking the original Doom code and updating it and the textures in it for higher res gameplay they took software written for a Nintendo 64 and updated that?!?
I suppose the original DOOM wasn't 64 bit... so I guess that would be the reason?