Old faithful - the reason that I still have an N64.
The combination of exploration and shooter hooks me in every time I go back to it. there is a weird kind of freedom in running headlong off the edge of a cliff trusting that a glimpse of a palm tree seen through the mists far below means that there is a platform for you to land on, it really does induce vertigo.
The hidden areas and bonus items keep you going back for more and the sound design also merits special mention - it's amazing how much ambience the developers managed to cram into an N64 cart.
Gamers who found disappointment in later outings on the more powerful consoles are urged to try this (and Seeds of Evil) to see how well this series started and how poorly the title is served by subsequent custodians.
Quality gaming from a golden age.