All-Star Team:
While at the title screen press Up, L, Up, L, Down, L, Down, L, Left, R, Right, R, Left, R, Right, R,
B, A, Z + Start. 

Big Head Mode:
While at the title screen press C-Up, C-Up, C-Down, C-Down, C-Left, C-Right, C-Left, C-Right, B,
A, Z + Start.