STAGE SELECT:
At the main options menu, press Up, Up, Down, Down, X, X, Left, Right, Left, Right, X, Triangle, X, Triangle. If you entered the code correctly, the options window will turn a transparent brown-red color. press START and press Left or Right to select a stage in any of the first six worlds.

CHANGE CLOUD SPEED ON THE TITLE SCREEN:
At the main options menu, press and hold L1 + L2 + R1 + R2. Then press Up and Down to make the clouds speed up and slow down