The Game Boy wasn't the first handheld gaming machine, but it was one of the most successful ones on its 1989 release. Combined with its successors, the Game Boy Color and Game Boy Advance, they would go on to sell more than 100 million units. It couldn't quite contain the NES' tech, but it managed to run 8-bit games with buttons and a D-Pad based on the NES' joypad.