Level select: Press Up(2), Down(2), Left, Right,
Left, Right, B, A, B, A,
Start at the title screen.
Extra lives: Press Up(4), Down(4), Left(4),
Right(4), Start at the title screen. Alternately,
pause game play and press Up(2), Down(2), Left,
Right, Left, Right, A, B, A,
B, Select, Start.
Sound test: Press Up, Down, Left, Right,
A, B, Start at the title screen.
Unlimited lives: Enter B32R as a password.
Level skip: Enter H2F2 as a password, then press Start
to advance to the next level.
