Fun game to play with friends, but doesn't justify the time spent since Turok 2 was released.
The graphics aren't exactly impressive (even with the expansion memory pack), but it's not so bad that you have to turn off the console.....and there are some great visuals to be had in multiplayer. Namely, shooting your friends with lethal shots of the inflater gun and watching them expand until they explode in a little shower of blood. The sound falls into the same category as the graphics, mediocre except when listening to the sound of the cerebral bore drilling into your friend's skull while his body twitches on screen. This is made better by the real life sound effects your friend is making of "Graaaah!".
Unfortunately, the multiplayer is only fun if you are playing it with ppl just to have fun, not competitively. Otherwise the slow character movement and ammo camping can ruin the experience. Monkey frag, however, will remain one of my fondest N64 memories. It was even fun to be the monkey.
Overall, I'd say this was a fair game....barely. But, if you are looking for a good buy in the N64 FPS genre I'd stick with Turok 2 or Goldeneye.