Game Boy
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The Game Boy was the first (excluding the Game and Watch line) battery-powered handheld game console sold by Nintendo, and was the third system that a portable Zelda game was released for, behind the Template:GW and Template:G&WZ. It was one of the world's best-selling game system lines, selling over 118 million units worldwide to date since the release of the original Game Boy[1], and has spawned many successful spin-offs, including the Game Boy Pocket.
The Legend of Zelda Games
The original Game Boy technically had one Zelda release: Link's Awakening. The first Game Boy Color Zelda title, Link's Awakening DX, could actually be played in black-and-white as a Game Boy game. However, a special dungeon, the Color Dungeon, could only be played on a Game Boy Color, as it was locked via a color-based puzzle at the entrance.