Select "Heavyweight" at first fighter attribute screen in career mode. Set the fighter's weight to "230" (maximum). Press X to go to the second fighter attributes screen. Change the fighter's body style from "1" to "2". Press Triangle to return to the first attributes screen. The fighter's weight can now be set anywhere from 230 to 280 lbs.
Box as a gargoyle
Enter "GARGOYLE" as a name at the boxer creation screen in career mode to unlock a gargoyle. Press Circle at the pre-fight ranking screen to save the boxer for use in career and exhibition modes.
Box as an alien
Enter "ROSWELL" as a name at the boxer creation screen in career mode to unlock an alien. Press Circle at the pre-fight ranking screen to save the boxer for use in career and exhibition modes.
Box as Ed Mahone
Enter "ED_MAHONE" as a name at the boxer creation screen in career mode to unlock Ed Mahone. Press Circle at the pre-fight ranking screen to save the boxer for use in career and exhibition modes. Note: "_" indicates a space.
Box as Jermiane Dupri
Enter "JERMAINE_DUPRI" as a name at the boxer creation screen in career mode to unlock Jermiane Dupri, the hip-hop musician. Press Circle at the pre-fight ranking screen to save the boxer for use in career and exhibition modes. Note: "_" indicates a space.
Box as Judge Mills Lane
Enter the options screen and view the "Cyber Athlete" video sequence. Then, enter exhibition mode and intentionally get disqualified. Mills Lane will now be unlocked as a middle weight boxer.
Box as Marc Ecko
Enter "MARC_ECKO" as a name at the boxer creation screen in career mode to unlock Marc Ecko, the founder of the Ecko line of clothes. Press Circle at the pre-fight ranking screen to save the boxer for use in career and exhibition modes. Note: "_" indicates a space.
Box as O
Enter "O" as a name as a name at the boxer creation screen in career mode to unlock the musician that performed most of the game music. Press Circle at the pre-fight ranking screen to save the boxer for use in career and exhibition modes.
Box as Q-Tip
Enter "Q_TIP" as a name at the boxer creation screen in career mode to unlock Q-Tip from the band "A Tribe Called Quest". Press Circle at the pre-fight ranking screen to save the boxer for use in career and exhibition modes. Note: "_" indicates a space.
Box as Shamcko The Clown
Enter "SHMACKO" as a name at the boxer creation screen in career mode to unlock a clown. Press Circle at the pre-fight ranking screen to save the boxer for use in career and exhibition modes.
Box as Tim Duncan
Enter "TIM_DUNCAN" as a name at the boxer creation screen in career mode to unlock Tim Duncan from the San Antonio Spurs. Press Circle at the pre-fight ranking screen to save the boxer for use in career and exhibition modes. Note: "_" indicates a space.
Box Marlon Wayans
Enter "MARLON_WAYANS" as a name at the boxer creation screen in career mode to unlock Marlon Wayans, the comedian. Press Circle at the pre-fight ranking screen to save the boxer for use in career and exhibition modes. Note: "_" indicates a space.
Extra Fighters
At the Boxer Creation screen, enter any of the following names to fight as that fighter. Then, at the Pre-Fight Ranking screen, press Circle to save the boxer:
JERMAINE DUPRI Q TIP O GARGOYLE MARC ECKO TIM DUNCAN MARLON WAYANS
Get up faster
Press Down + X after being knocked down to get up faster.
Illegal kick
During a match, press Triangle + Circle + X + Square to illegally kick your opponent in the midsection.
Miniature boxers
Enter "MINIME" as a name at the boxer creation screen in career mode to miniaturize all boxers. Enter "RESETPASS" as a name at the boxer creation screen in career mode to return to normal size.
