Unlock Stadiums 1, 2, 5, and 11:
     At the Arcade Mode menu, press B, Up, Y, Left, A, Right, Down.

Unlock Stadiums 3, 7, 10, and 15:
     At  the  Arcade  Mode  menu, press B, A, Left, Left, Start, B, A,
Left, Left, Start.

Unlock Stadiums 8, 13, and 16:
     At the Arcade Mode menu, press B, A, Right, Start, B, A, Right, Start.

All-Star Teams:
     At the Arcade Mode menu, press Start, A, Y, Up, Right, B, A, Down.

Silicon Dream Teams:
     At  the  Arcade Mode menu, press Y, A, B, B, A, Down, A, B, B, A,
Down, Up.

Small Players:
     At  the  Arcade  Mode menu, press Down, Up, Left, Left, A, Right,
Down, Start