All hidden games:
Press L1, R1, R2, L2, Select,
Start at the title screen to unlock Bubble Bobble,
Cameltry, Kiki Kaikai, Metal Black, and Syvalion.



Bubble Bobble:
Play all default games at least one time.

Cameltry:

Accumulate at least one hour of game play in Lunar
Rescue, Ah Eikou no Koshien, Alpine Ski, Cleopatra
Fortune, Puchi Carat, and Flipull.

Kiki Kaikai:
Accumulate a total of five hours game play.
Metal Black:
Accumulate at least one hour of game play in Space
Invaders Color, Space Invaders DX, Darius Gaiden,
Grid Seeker, and Majestic Twelve.


Syvalion:

Accumulate at least one hour of game play in Elevator
Action Returns, Kuri Kinton, Jigoku Meguri,
Don Doko Don, Rastan Saga, Fairyland Story,
Pulirula, Lightbringer, and Runark.