Home Run KING is an arcade-style game by the same development team responsible for 2000's World Series Baseball 2K. The game features both MLB and MLBPA licenses, allowing for authentic teams, stadiums, and players with abilities based on the 2001 season. Players can swing for the fences in a Home Run Derby or participate in the more traditional Season, Exhibition, or Playoff modes. A Create-Player option is also available for players to generate up to 40 athletes, customizing such details as glasses, socks, and facial hair.
The batter-pitcher interface is cursor based, with the ability for a batter to increase his chances of making contact by correctly guessing the pitch before it is released. Players can also elect to field the ball manually or have the computer assist in tracking the ball. In addition to fielding assistance, individual slider bars let players tweak the amount of help in batting and pitching. Other options include toggles for wind, errors, automatic replays, and the rumble feature. Games can also be played on one of five difficulty levels, three times of day, and in three weather conditions.
Home Run KING also keeps track of three types of records: performance in the Home Run Derby, the number of World Series championship rings, and points after playing an Exhibition game. Players receive points for each hit, with more points awarded for extra base hits, while deductions are made for giving up runs or striking out. The top ten overall performances are saved to memory card. Finally, players can manage rosters by making trades, adding free agents, adjusting rotations, and changing starting lineups.