Power Stone

Full pause screen:
Pause game play, then press X + Y.

Alternate costumes:
Press B at the character selection screen.

Extra Options:
Successfully complete arcade mode as any character under any difficulty setting. An "Extra Options" selection will be available.

Extending pole:
Successfully complete the game using any single character.

Heavy chain gun:
Successfully complete the game using any two characters.

Ray gun:
Successfully complete the game using any three characters.

Shield:
Successfully complete the game using any four characters.

Falcon's mini-game:
Successfully complete the game using any five characters.

Ayame's mini-game:
Successfully complete the game using any six characters.

Gunrock's mini-game:
Successfully complete the game using any seven characters.

Fight as Kraken:
Successfully complete the game with all eight characters to unlock Kraken.

Fight as Valgas:
Successfully complete the game as Kraken to unlock Valgas.

Fight as Mutant Fusion (Final) Valgas: 
Unlock Valgas, then successfully complete the game with any character without using continues under any difficulty setting. Enter the page 12 of the Power Stone Collection to see Final Valgas. Note: Final Valgas may only be selected in versus mode, by only one player per match.

Virtua battle mode:
Unlock Valgas as a playable character and use him to successfully complete the game. Virtua battle mode will be available on page 5 in the Power Stone Collection. This mode allows the camera to stay behind your character during a match.

Dual Virtua battle mode:
Unlock Kraken as a playable character and use him to successfully complete the game. This mode will be unlocked on page 6 in the Power Stone Collection. This mode allows a versus mode game to be played with the Virtua battle mode camera angle on each part of the split screen.

Alternate costumes:
Press B at the character selection screen.

Scrap book:
Accumulate 1000 or more coins in the VMS mini-games to unlock a scrap book (art gallery) option on page 13 of the Power Stone Collection.

Sound test:
Accumulate 2000 or more coins in the VMS mini-games to unlock a sound test (sound gallery) option on page 25 of the Power Stone Collection.

View ending sequences:
Successfully complete the game with any character to access page 14 of the Power Stone Collection. This may be used to view the endings of any character that has completed the game or the game's credits.

Change victory view:
Press the D-pad or Analog-stick to change the viewing angle at the end of a match. Press A to move the camera in.

No damage:

Enable "Extra Options" code. Enter the extra options screen and set "Transformation Damage" to "0%". Start another match, collect three gems, and transform. Do not use any regular attacks on your opponent after transforming. Instead, throw objects to keep from getting damage.

출처 : http://www.gamewinners.com/DC/PowerStone.htm