The Game Boy was Nintendo’s first handheld game console and it combined features from both the Nintendo Entertainment System and Game & Watch. It was sold either as a standalone unit 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 outsold its rivals and became a significant 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, its entire shipment of one million units was sold within a few weeks. Production of the Game Boy and Game Boy Color were discontinued in the early 2000s, being replaced by the subsequent Game Boy Advance, released in 2001.