It is a secret race level which can be reached by entering a picture in a hidden room in Peach's Castle.
When Mario enters the level he will start out in a small room. At the left side, a sign can be seen which holds the racing instructions. At the right side is a hidden blue coin switch which will spawn coins on the racing track for a limited time, if Mario activates it.
Mario starts the race by crossing the starting line.
There are two ways to race:
- If Mario just runs onto the track, he will start sliding while sitting. If the player slides like this, they will be able to break better, but won't be fast.
- Mario can also start the race by dive jumping onto the track, giving him extra speed, but making controlling him harder and breaking almost impossible, making unfenced sections of the race track very risky. If the player doesn't take enough care while sliding like this, Mario will fall off the race track into the void and lose a life.
Mario finishes the race by crossing the finish line. At the end of the race, he will be in another small room with a stage and a yellow ! box hovering in mid-air. If Mario hits the box, he will get a star.
This level actually has two stars. The first one is the one Mario gets from the ! box, while the other one only appears if Mario slides fast enough. If Mario is fast enough (a time of less than 0'21"00), the second star will spawn from him as Mario crosses the finish line. However, be careful, as Mario is only able to collect one star at a time as collecting one of the two stars causes him to exit the secret slide, thus the player has to enter the secret slide twice to get both stars.
You would be advised to take the the second star, if you are fast enough to spawn it, or take the first star, if you weren't fast enough to get the second one or already have collected the second one.
If you reenter the level, you can exit it by recollecting the now blue star from the box.