Star Fox 64 had quite a few different ways of playing it. There were a few routes that you could take, a few ways to play certain levels, and special goals to accomplish throughout. In short, the game has a lot of replay value to it, not mentioning how fun it is. The N64 version did not have the ability to save. I'm pretty sure it was not a technological issue, seeing as how other games could save on the system. The game was meant to be played in on sit down, which added depth to the game in a way.
The most important thing about the game itself was that it was down right fun. You had three team mates with dialogue of their own through the levels, and at times they needed help fighting off enemies, or even gave you assistance, like Slippy bringing up the shield strength of the boss you're fighting against. This too adds replay value. You go into a new game, thinking to yourself "which route will I take this time? Which members of my team will make it? Will I get the goals achieved?"
There are so many thing to do in such a short time, it makes it worth going through plenty of times. I myself have played the original N64 version so many time I lost count, on both the N64 itself and the virtual console from the Wii. This game could help a kid who is active outside during a rainy day, help a young adult on a car ride to visit family members, give an old school fan a taste of sweet nostalgic greatness. That's what two hour can do with this game.