Fight as Boss:
Press Up, Right, Down, Left, B at the mode selection screen. Choose two player mode to access the Supervisor Robot as a fighter.

View animation sequences:
Press Left, B, Right, B, Down, Left, Right, B at the player selection screen.

Invincibility:
Press Down, B, Up, B, Down, Left, Right, B at the player selection screen to be invincible in trainer or missinon modes.

Super moves:
The following super moves may be used in a two player game after activating that selection at the option screen.

Reverse opponent's controls
Forward(3), Forward + Any Button

Take no damage
Back(3), Back + Any Button

Invisibility
Up(3), Up, + Any Button

Disable Special Moves
Down(3), Down + Any Button