Power Pro Kun Pocket is a baseball simulation game for the Game Boy Color, released in Japan. It likely features simplified baseball gameplay suited for the handheld platform.  Specific details about the game's modes, features, and overall complexity require more research.  The game was probably developed and published by a Japanese company, with a focus on recreating aspects of the popular Power Pro Kun baseball franchise for the Game Boy Color audience.

Power Pro Kun Pocket (Japan)

Pop'n Pop (Europe)