Enter "NEWVIEW" as a first name in Create Champ mode to unlock all venues.
Bonus venues
Win a match at one of the corresponding venues in Career mode to unlock it:
Madison Square Garden
The Staples Center
Box as Ko Rey Mo
Defeat Ko Rey Mo in the light heavy division in Career mode to unlock him.
Burger King trainer
Win the Burger King event in Career mode. Then at the trainer selection screen, press Down until the Burger King appears as a choice. He gives you Heart when you fight.
Boxing styles
Win matches in ESPN Classic Fights mode or Career mode to unlock various new styles, at random:
Hard Straights
Hook Master
Judge Jab
Lethal Uppercuts
Philly Shell
Sinister Cross
Slickster
Smooth
Textbook
Uptight
Easy wins in Career mode
Go to the options menu and set "Illegal Blows" to "Off". Then, go to the fight store and buy the illegal head punch called "Elbow Shot". During a fight, use the Elbow Shot to counter attack each time your opponent throws a punch. Note: Make sure you use the Elbow Shot as a counter attack so that you can connect cleanly and powerfully on you opponent's head. You will see that the Elbow Shot inflicts a lot of damage to your opponent, and will KO him in a short period of time, or TKO because you inflicted so much damage to his eyes.