Ken Griffey Jr.'s Slugfest, known in Japan as ケン・グリフィーJr.のスラッグフェスト, is a baseball video game released for the Nintendo 64 in 1999. Developed by Angel Studios and published by Nintendo, it is the third game in the Major League Baseball series, following Ken Griffey Jr.'s Winning Run in 1996. The game features both single-player and multi-player modes, allowing up to four players to compete in a game of baseball. The game also features an extensive character customization system, where players can create their own team, customize the players and even create their own stadiums. The game features a variety of play modes, such as Exhibition, Season, Playoffs, Home Run Derby and All-Star Game. Players can also customize the rules of the game, such as the number of innings, the number of players, the number of teams and the difficulty level. Ken Griffey Jr.'s Slugfest features a variety of realistic animations and sound effects, as well as a wide selection of teams and stadiums. The game also features a wide variety of power-ups, such as the Super Star power-up which gives the player an extra hit, and the Super Speed power-up which increases the speed of the player's character. Overall, Ken Griffey Jr.'s Slugfest is a fun and engaging baseball game that will appeal to both casual and hardcore fans of the sport. With its realistic animations, sound effects and wide variety of play modes, the game is sure to provide hours of entertainment.