Fight as Pride:

Beat basic mode with seven different characters.

Fight as Mel:

Beat basic mode with eight different characters. She is the girl from the shop mode and has a similar fighting style to Julia.

Fight as Character In Transformed Body:

Go to Power Stone collections. Turn to the third page and hold select. Simply press X, Y, Y, B, A, X, Left, Right and up. When your done go to the character select screen in any fighting mode. Now when you play with any character its body will be transformed throughout the whole game.

All Weapons:

Play the game as Jack or Wangtang in the level with the rolling rock. When the floor breaks, you will be chased. If you are Jack during the escape, jump twice and land in the first hole you see. Quickly press X, X, Y, B, A. You will here Jack laugh if you get this right. If you are Wangtang jump once and land in the second hole, you see. Quickly press Y, Y, B, X, A. You will hear Wangtang talk if you get it right. When one of these is entered right you'll get all weapons.

Extra Arenas:

Beat basic mode with all characters, including Mel and Pride to unlock three new arenas exclusive to original mode. To access them, move the pointer left or right at the arena selection screen until it is off-screen. A large box with the "Extra Arena" message will appear. Select the desired extra arena. The arenas are a small room, a very narrow bridge over along drop, and geometric (cubes stacked in weird patterns) arena.

Unlocking the Options in the Extra Option Menu:

Every time basic mode is cleared with a different character a new option will be unlocked, until the extra option menu is full.

100,000 Credits for Shop Mode:

If during the course of the game you manage to pick up item #103, which resembles a red turban, sell it for 100,000 credits in shop mode. This item seems to appear randomly.

Infinite Money:

Go to Extra options. Before you do this check to see if you beat the game with two people. If you have go to Extra Options and press Select twice. A white screen will appear. Quickly press Y, B, B, B, A, Y. You will now return to the main menu. Go down to Power Stone Collections and you will see Infinite Money in yellow writing. Turn it on by pressing the right button on the control Pad. Now when you beat the levels in any stage you can buy anything.

Magical Sword:

Not really a cheat, but in the Japanese Castle level, in the end with the giant gong, in the left corner, with the sword rack if you use the flamethrower on it a magical sword will appear, though I am not sure what it does, there is some blue lights flashing around you.

Practice Against Boss:

Beat basic mode with all characters including Mel and Pride. Then go to original mode and have two people battle. When you get to the stage selection screen there should be two extra stages with the boss in the picture. You can practice against the bosses.

Brutal:

In order for this code to work first go to Original Mode and pick two Players but there have to be more than two people playing in Original mode. You should notice that everyone has a different color 1st Player is Red 2nd Player is Yellow. Now turn Player two's color Red and pick your Fighter. For Example: Wangtang and Ryoma when the fight starts go to Wangtang as if you want to Pick him up and Ryoma will jump off of him and drop kick the other person you are fighting if he catches them he will Stab them with his Katana about 10 times. This trick is also a good way to take Gems from a person who just got there super.

Full Pause Screen:

Pause game play, then press X + Y.

Cool Weapon Combinations:

Flame Thrower Flame element + gun
Fire bottle Oil + flame element
5-way Shotgun 3-way shotgun + drivers licence

In adventure mode on the flying airship level, once you have skydived, where the waterfall is you will see that loads of cards drop from there. This is the ideal spot to pick up cards free!