When creating a character, set his heart, power, and speed high. It is important to have the heart high. If you jab a lot then throw a punch, it will work much better than just bashing the buttons.
Game Shark Codes
Master Code (Must Be On) 0E3C7DF2 1853E59EEE8B7E3A BCCA4112
Infinite Creation Points FEBE644E BCA99B4BFEABA39A BCA99B4B
Max Stats Created Character DEBE6476 BBA89A82CEBE6472 BCA99A82
Max Power FEBE6476 BCA99B82
Max Speed FEBE6471 BCA99B82
Max Stamina FEBE6470 BCA99B82
Max Chin FEBE6473 BCA99B82
Max Heart FEBE6472 BCA99B82
Max Cuts FEBE647D BCA99B82
8 Foot Created Character CEBE646A BCA99BE3
9 Foot Created Character CEBE646A BCA99BEF
300 Pound Created Character CEBE6474 BCA99CAF
400 Pound Created Character CEBE6474 BCA99C13