Well, that question is quite easy to answer. The Sega Game Gear as we all know is a hand-held (i. e. portable) color video game console. It was first made available to the public in 1991. First, there were only seven games - Castle Of Illusion Starring Mickey Mouse, G-Loc, Shinobi, Woody Pop, Factory Panic, Super Monaco GP, and Wonder Boy (Drancon's Revenge). If you bought a Game Gear you got the main console (of course) plus the game Columns and a little strap to attach to it for even better portability. It was nearly twice as expensive as arch rival Nintendo's Game Boy, so not as many people were attracted, but those who knew (like me :-)) did of course only regard the quality and not the price difference. Later, Sega also made up the 4-Fun pack, including a four-game-in-one cartridge, and a bundle including not Columns but Sonic The Hedgehog plus an AC adaptor. And the price lowered too. But still the Game Boy was far ahead at the peak of the sales charts.
Of course a lot of games followed the orginal seven, of which most were adaptions of titles from the Sega Genesis / Mega Drive or Master System. The most popular among these include Sonic The Hedgehog and its countless sequels, the Shinobi series, a couple of Simpsons games, a lot of Disney movie / comic character based games, the Streets Of Rage saga, two Wonder Boy games, the several Mortal Kombat episodes, Prince Of Persia, Lemmings, Ecco The Dolphin and its sequel, NBA Jam and NBA TE, a few movie adaption games like Jurassic Park or Star Wars, and more. Not all of these games are of course good, and there's also a whole lot of pretty unknown games that are as good or better than most popular titles. Generally, if you have one game and compare its Game Boy and Game Gear versions, you will have to admit that the Game Gear's version is altogether better, not only because the GG is in color but also because it technically can do more complex stuff in some cases. The GB's only advantage is that its screen resolution is a bit higher... but hey, what's the use of a higher resolution if there's only half a dozen of gray shades? Then, the GG needs more power to do its stuff properly, so a set of batteries (consisting of six) will be pretty damn used up after 1 to 1 1/2 hours. You should buy rechargeable ones if you play without a power plug in reach frequently.
Technically, what I can say about the Game Gear is this:
|CPU:||Z80 CPU (3.6 Mhz, 8 bit)|
|Graphics:||8 bit, 4096 colors, 32 at a time|
|Sprites:||64, 8x8 pixels each|
|Screen:||3.2 inches in diameter, 160x144 pixels|
|Audio:||4 audio tracks for music and sound effects (mono, stereo with headphones), able to play digital audio samples|
|Cartridges:||Up to 8 megabits (512.000 bytes) in size, up to 16 bit|