Battle flipper controls both flippers:
Press Up, A, Right, B, Down, Left at the title screen.

Five balls in pinball:
Press Left, Right, A, Down, B, Up at the title screen.

Ten balls:
Press B, Left, Right, A, Up, Down at the title screen.

Use flipper with highest rebound:
Press Down, B, Left, Right, Up, A at the title screen.

Alternate vertical flipper control:
Press Right, Up, B, Left, A, Down at the title screen. In pinball, controller one will control the bottom flipper and controller two will control the top flipper.

Alternate horizontal flipper control:
Press A, Down, Up, Right, Left, B at the title screen. In pinball, controller one will control the flipper on the right side and controller two will control the flipper on the left side.