Level select Enter the options screen. Set "Vibration" to "1" and "Sound
effects" and "Music" to "0". Then, hold
L1
+ L2
+ R1
+ R2
+ Circle
+ Square.
The message "Spooky Cat" will appear in the center of the screen
to verify proper entry.
Ending bonuses Finish the game in the hard difficulty setting. The maniac
difficulty setting and a bonus helicopter and will now be
available. The bonus helicopter flies, turns, climbs, descends,
and shoots faster.
Finish the game in the maniac difficulty setting to access a
third bonus helicopter, which you can use on any difficulty
setting. It has the identical top speed and fire rate as the
second bonus helicopter, but more armor.