Gameplay
(needs to be ported to the wiki!)
X2 does not deviate greatly from X, but it does offer some interesting new things. First, X starts off with the ability to dash in the game, though he lacks all other abilities he may have gained in X1. The various armor pieces he gains in X2 offer him different abilities, even though his advanced buster still allows all weapons to be charged. X’s upgraded boots also allow him to dash through air, which allows X to evade enemy attacks easier and reach new places.
It should also be noted that your actions in this game will influence the final boss fight, a factor that definitely didn't appear in the first X game. As you make your way through the game, you have the option to retrieve Zero's stolen body parts, which will allow you to skip over the Zero fight at the end of the game.
Aside from this, the game is more or less the same when compared to the original X game. Level design improves a lot as it involves optional sub-bosses and other interesting environmental features. Even the weapons available in X2 seem to have improved over the ones in the first X game.
Story
(needs to be ported to the wiki!)
It has been a short six months since Mega Man X defeated the Maverick leader Sigma and what appeared to be the last of his followers. The cost was great, though, as Zero, the leader of the Maverick Hunters and a good friend of X, sacrificed his life in order to defeat the Reploid Vile in his powerful suit of armor, which allowed X to finish off Sigma and the remaining Mavericks.
Thanks to a tip-off by Dr. Cain, X and his fellow Maverick Hunters have tracked the "last" of the remaining Mavericks to an abandoned factory where Giant Mechaniloids are being produced. As X and friends prepare to destroy the remaining Mavericks, they are unaware of the real danger that awaits them, for a new group of Mavericks has arisen.
Not only are there eight new Mavericks in the world; a group of three extremely powerful Mavericks has dubbed themselves the "X-Hunters," and -as you may have guessed- are intent on finding and destroying none other than Mega Man X. Even worse, they've broken into Dr. Cain's lab and retrieved Zero's three remaining body parts.
Could they be planning to revive Zero, an all-powerful Reploid with previously-good intentions, and program him to fight for evil? It's up to X to retrieve Zero's body parts, fight off the eight new Mavericks, and put an end to the mysterious criminal mastermind behind this dodgy business.