GT 64 was a poorly received racing game designed to be a simulator, like Gran Turismo. There are 14 accurate, real, GT teams, yet only 3 tracks to race them on. There is a 2 player mode, but frame rate tends to drop significantly when racing someone else.
Before races, you have the option of tweaking your car. Things like suspension, tires, or steering can affect how your vehicle preforms. When the race begins, 7 other NPC cars are also participating. However, due to programming limitations, no more than 3 will appear on screen at the same time.