There are a number of changes in this game to the boxer's names from the original Japanese version:
Rocky Smith is known as Jabbin' Jim.
Joe Vulcan is known as Gentleman Joe.
Mr. Mohican is known as Knockout Nick.
Mark Rentz is known as Steel Fist Fritz.
Avege Hidev is known as Bronx Bruiser.
Marvin Cobra is known as Harlem Hit Man.
Most of the voice samples have been changed from Japanese to English, and a few Easter Eggs are not included in the American release. These include a flock of birds appearing in the ring at the start of a fight (damage based), an alternate head (Moai) for the referee (time based), a bonus hidden in the Power training session, and two different circuits (game modes) made accessible via joystick input at the beginning of a new game.