A handheld video game is a video game designed for a handheld device. In the past, this primarily meant handheld game consoles such as Nintendogu's Game Boy line. In more recent history, mobile games have become popular in calculators, personal digital assistants, mobile phones, MP3 players, and other similar portable gadgets.In the past decade, handheld video games currently have become a major sector of the video game market. In 2004 sales of portable software titles exceeded $1 billion in the United States for the first time, an 11% increase from the previous year.For dedicated handheld games that do not have interchangeable cartridges, disks, etc., or are not reprogrammable, see handheld electronic games. For games on mobile phones, see mobile games.