Three years after the events of Final Fantasy VII, an unknown group of powerful SOLDIERs appear, bringing a swift and bitter end to the peace enjoyed by the people of world. The members of this enigmatic group are the ones who were trapped under the ruins of Midgar for three long years; the Deepground SOLDIERs, their intention is to call forth the final WEAPON, Omega, before its time. However, to do that, the DGS need Vincent to lead the way to Omega.
Vincent Valentine finds himself pursued by several elite members of the mysterious organization. An unrelenting chain of events leads Vincent to the truth behind his past and forces him once again to be the key player in a battle for the planet itself and all those living in it.

Reeve Tuesti, former Head of Urban Development at Shin-Ra (as well as the remote pilot of Cait Sith), is now the leader of the World Regenesis Organization, which looks after the planet and prevents people from damaging it further. Yuffie Kisaragi is another member of the organization, and several other characters from the original game provide the WRO with outside assistance.

The game begins with an FMV depicting the attack on the town of Kalm, an attack carried out by Deepground militia. Vincent thwarts the attack, but not before encountering Azul and Shelke, members of the Tsviets, Deepground's elite force of supersoldiers.

The game is a third-person shooter role-playing game that also incorporates RPG elements such as hit points and usable items. The player can switch to first person view mode and utilize a cross hair to shoot enemies. Vincent has an HP Bar, as well as magic ponts (MP). There is also a value for Level, where Vincent can level up by eliminating enemies. Vincent can also choose weapons from a large library, primarily guns. The option of transforming into his Limit Breaks is also available, the first being Vincent's first limit break, the Galian Beast, and the second is Chaos.

( Reference: http://na.square-enix.com/dcff7/ )