Handheld video games grew out of handheld electronic games that were popular from the 1970s through the mid 1990s. The key factors in contributing to the advance of handheld video games were the increase in processing power, technological advances in liquid crystal displays (LCDs), and the reduction of power requirements. Handheld video games grew immensely in popularity, thanks to the Game Boy released in 1989. Tetris was considered the "killer app" for the console, and popularized the action puzzle genre.
