K.O.: The Pro Boxing

K.O.: The Pro Boxing for the Game Boy Color centers its action around the Chiba Gym, where standard bouts and competitive events take place. A player can engage in one-off fights by selecting from a roster of eight established boxers.

Alternatively, a tournament path is available, which requires a personally defined fighter. This custom boxer is built by choosing a name, facial appearance, and trunks, while also having underlying performance statistics. These attributes can be improved through training activities to enhance the boxer's capabilities for matches.

The tournament structure operates on a scheduled calendar, dictating the timing of the boxing matches the created athlete must participate in.