The Game Boy is Nintendo's second handheld system following the Game & Watch series introduced in 1980 and it combined features from both the Nintendo Entertainment System and Game & Watch. It was either bought as a standalone console or bundled with the puzzle game Tetris.
During its early lifetime, the Game Boy mainly competed with Sega's Game Gear, Atari's Lynx, and NEC's TurboExpress. The Game Boy beat its rivals and became a tremendous success. The Game Boy and its successor, the Game Boy Color, have sold over 118 million units worldwide. Upon the Game Boy's release in the United States, it sold its entire shipment of one million units within a few weeks. The Game Boy and Game Boy Color were discontinued in the early 2000's in favor of the subsequent Game Boy Advance, released in 2001.