Game Boy is the most successful video game system ever developed. Since its introduction in 1989, Game Boy has sold well over 150 million systems worldwide. Over the years, Game Boy's software library has included some of the greatest and best-selling games of all time, such as Tetris and Pokémon. Game Boy evolved over the years and has appeared in many colors and sizes, including the smaller sized Game Boy pocket in 1996 and Game Boy Color in 1998.