New Super Mario Bros.
Race tracks
Diddy Kong Racing contains twenty race tracks split between five worlds. In most races (marked with a check mark), racers are able to choose what type of vehicle to bring into the race, which can effect the paths in the course they are able to take. For some races, there are vehicles that are not able to be taken into it (marked with a red X). Every race also has a default vehicle type to use (marked with a D), which is usually the best type of vehicle to use for the race.
Challenge Levels
A Wish Key unlocks a door leading to a Challenge Level.
Challenge Levels are challenges that appear in each of the four main worlds. Each world has a single Challenge Level that matches the world's theme, and has a unique objective and layout. Each Challenge Level's door can be unlocked by a Wish Key located a specific course of that world. The player obtains a part of the T.T. Amulet when they win at a challenge.