Big Heads
     At  the  Title  screen,  press C-Up, C-Up,C-Down, C-Down, C-Left,
C-Right, C-Left, C-Right, B, A, hold Z, then press Start.

Extra Teams
     At  the  Title screen, press Up, L, Up, L,Down, L, Down, L, Left,
R, Right, R, Left, R, Right, R, B, A, hold Z, then press Start.