Kickball

After the team select screen, choose 'password'

Enter the 2 player mode and at the character selection screen, hold Up + II and press Run to select your player. After Player 2 picks his character, you'll be able to play with a hidden character.

Select your Team, and enter the following password to start on the corresponding Match. If you enter the Next Season passwords, you will start the game against the CPU in alternate costumes.

Enter the 1 player mode, pick your character and at the "Playball" screen, hold Select and press Run. If done right, the screen will go black. Now press Left, Up or Right to start on different stadiums.