Race families

There are 3 race families in this game. Each corresponds to a different set of rules:

1. Distance: You start with a small amount of energy and can gather more by hitting distance checkpoints located regularly along the track. The goal is to go as far as possible before your fuel reaches zero.
2. Laps: You need to drive around the track as fast as possible, for one lap exactly.
3. Relay: You need to drive around the track as fast as possible for one lap, but the car category changes for each sector, so you need to drive a vehicle from each of the 3 categories.