Surprisingly I never got a chance to play the original on the computer, but the N64 version seems to portray the insanity well. As I understand it the weapons, enemies and level textures are the same, but the actual level designs are N64-exclusive, which is a neat touch. Much like the first Quake it's not a thinking man's shooter like Perfect Dark or GoldenEye, but there are some surprising elements such as the enemies that take potshots at you in their death throes. And while there's no online component, it offers a commendable split-screen experience.