It was far from a perfect game that's for sure, but it combines the elements of FPS, mission objectives, great level design (you might want to read how they managed to get some textures to fit the limited memory of the N64), a compelling story (that wasn't an exact replica of the movie, too many games make that mistake), couch/splitscreen multiplayer along with cheats you could unlock by being good at speedrunning.

All together, those made a great game for its time.