Family Circuit '91 is a follow-up to the racing game Family Circuit. Like the previous game, it offers plenty of customizable options for the player to take account of. Players have the options of setting the color of the car, can tune the engine to their liking, can adjust the car's transmission, suspension, brake, and steering settings, set the angle of the wing, and choose the softness or hardness of the tires. The game also features 24 different tracks from around the world to race on.

Four racing modes are available:

- Free practice: Players can practice solo on a track of their choice.
- Time attack: Players compete against themselves and try to race around a track as fast as possible.
- Sprint race: Race a season in three different series – Novice (consists of four races), Japan (consists of seven races), and World (consists of sixteen races) – Players compete for first place against seven other racers. Players earn points depending where they finish in a race. After all the races are finished, the car who earned the most total points wins the entire series.
- Endurance race: Players pick from one of the ten offered tracks. Cars in this mode are forced to race more than the typical amount of laps.