Level select
Press [Left], [Up], [X], [Up], [Right], [Y] when "Press Start" appears on the opening screen. The screen will flash to confirm correct code entry. The level selection screen will appear when a new game is started.
Unlimited health
Press [L] + [R] + [Y] + [A] + [Analog-stick Left] when "Press Start" appears on the opening screen. The screen will flash to confirm correct code entry.