Four continues:
Quickly press C, R, Right,
Down on the start/options screen.
Zone select:
Press Z, Down, L, Up on the
start/options screen.
Auto-fire:
Press B, Up, L, Right on the
start/options screen.
Hidden difficulty levels:
Press L, Right, Down, Left on
the start/options screen. The "Abnormal" and "Very Easy"
difficulty levels are now unlocked at the options menu.
