Sega's only handheld game console ever made was the Game Gear. It has the same controls as the Master System. The console requires six AA batteries to function, and they only last for a very short time of 3-5 hours.
The Game Gear was released in Japan on October 6, 1990, and in North America and Europe on April 26, 1991. The original price for this console was $149.99. Despite its powerful systems, the Game Gear was largely criticized by Sega's fans, and it only sold over 10 million units through 1996, before it was discontinued in 1997.
Some notable games for the Sega Game Gear include Sonic the Hedgehog (1991), Sonic the Hedgehog 2 (1992), Sonic Chaos (1993), Sonic the Hedgehog: Triple Trouble (1994), Sonic Drift 2 (1995), and Sonic Blast (1996).
Nintendo vs. Sega
The Game Gear competed with its Nintendo counterpart, the Game Boy. Compared to this console, the Game Gear has a large color palette of 4,096 colors, way more than what you'd expect on an ordinary Game Boy (which is nothing but black and white), but not as much colors as the Game Boy Color, the successor of the first Game Boy, released a year after the Game Gear was discontinued.
- http://www.sega.com/products/hardware/gamegear (1996-1999)