[M] Must Be On
91F12AFE 1899
1C788D16 2ECD
CE1D1D6B CA1F

Unlock Yugi
B22558A5 9C95

Unlock Bakura
D6AD5CA7 DE9D

Unlock Kaibaman
92AD5CA5 9C9D

Unlock Grandpa
AA21D87D 8C15

Have All Maps
55FC6BA0 7CF0
2B446E05 0E68
C19419A5 7853

Have All Map Types
11FC2BA6 3EF0

Infinite LP
DBB3ED57 4420

Delete Opps. LP [Press Select+Up]
0C7BAFDE A126
D8B0FD17 6AEF
9E1C5D27 0BDE 

Unlock Characters

At the title screen, press these codes in to unlock the character.
Code Effect
Grandpa
Down, B, Left, Right, Right, R, Up and R, A Kaibaman
L, Down, Right, Left and B, R, Down, Down, A Yami Bakura
R, Left, B, Right, Up and R, Right, Down, A Yami Yugi
At the title screen press L, Right + B, Right, B, R, Left, Down, and A
Unlockables
Unlock New Maps and LM Types

Unlockable How to Unlock
Chicago Map Win once with Dark Magician Girl
Desert Map, and new LM type Beat one level as Mai
Desert Stage Win as Mai Valentine
Graveyard Map and new LM type Beat the game with Yami Bakura
Inside The Puzzle Map, and new LM type Beat one level as Yami Yugi
Kaiba Corperation Map, and new LM type Beat one level as Kaibaman
Mayan Ruins stage Win as Rebecca Hawkins
Space World map & a new LM type. Win 1 game with Kaiba
Toonworld map & a New LM Type Win 1 game with Pegasus

Unlock new worlds

Here how to unlock some board maps
Unlockable How to Unlock
Above Tibet Beat 1 round with Grandpa
Domino Pier beat one level as Joey
Kaiba Land beat one level as Mokkuba

Here are some cheats and tips

Grandpa
At the title screen, press L, Right + B, Right, B, R, Left, Down, A. Note: Do not enter the code too quickly.

Kaibaman
At the title screen, press Down, B, Left, Right(2), R, Up + R, A. Note: Do not enter the code too quickly.

Yami Bakura
At the title screen, press L, Down, Right, Left + B, R, Down(2), A. Note: Do not enter the code too quickly.

Yami Yugi
At the title screen, press R, Left, B, Right, Up + R, Right, Down, A. Note: Do not enter the code too quickly.

Chicago map
Win a game with Dark Magician Girl to unlock the Chicago map.

Domino Pier map
Win a game with Joey to unlock the Domino Pier map.

Kaiba Land map
Win a game with Mokuba to unlock the Kaiba Land map.

Ruins map
Win a game with Rebecca to unlock the Ruins map.

Space World map
Win a game with Kaiba to unlock the Space World map.

Toonworld map
Win a game with Pegasus to unlock the Toonworld map.

Scroll text faster
To make the text go faster, hold B.