The SEGA Mega Drive version of Sonic the Hedgehog 2 will always be a classic and making a perfect sequel when it comes to video games as a whole. What many people did not know including myself that the Game Gear version of Sonic the Hedgehog 2 takes places before the Mega Drive version on how Sonic and Tails became best friends; where in the Game Gear version Tails gets kidnapped by Dr. Robotnik and it's up to Sonic to rescue Tails and collect the six Chaos Emeralds.
For a handheld game for the Game Gear it does hold up for an 8-bit version of the game, but on a smaller screen, with 7 levels well six if you don't collect all six Chaos Emeralds you'll get the bad ending so it's making you have to collect them if you want to unlock the final level. Each of the 7 levels will have three acts for each one where two of them will be the stages and the third being the boss stage; seems simple enough for any average Sonic fan the problem that some gamers may have is how small and cramped some of the stages can be for certain stages and not knowing what's coming ahead. One example is the first level being the Under Ground Zone, where spikes from above will drop at certain moments, enemies will pop up out of the blue and jump across certain platforms while riding a mine cart. The later levels offer a fair challenge just keep an eye out for one of the Chaos Emeralds scatted across through certain stages. You do get a hang glider for the second stage being Sky High Zone but you don't get full control of the hang glider it'll just have a mind of its own, but the water level feel a little easier since you'll have a bubble which will make you float but it's about timing and patience as you move while avoiding spikes and enemies.
I do like the soundtrack for most of the levels, one track in particular being Green Hills Zone would be later used in Sonic CD opening for the Japanese and European release. The gameplay controls feel simple and easy to pick to play using the directional pad to move or roll to break certain walls or enemies and using 1 or 2 to jump; the only problem that some people will have is that this version of Sonic the Hedgehog 2 can be a little challenging with a few frustrating moments if you are not too careful so I wouldn't suggest rushing through the game.
You can easily pick up this game on most platforms where the Game Gear versions have been ported to Sonic Mega Collection on the PS2, Xbox and Game Cube. This has also been released on Nintendo Virtual Console as well, but overall both the game is cheap to get if you own a SEGA Game Gear or the SEGA Master System and both systems are region free. If you are curious about playing this version of Sonic the Hedgehog 2 it's not the best in the series, but has its moments if you can get past the frustrating parts.