Final Fantasy Versus XIII is an action role playing videogame developed and published by Square Enix. The game is exclusive to the PS3.
For the first time in the series' history, Final Fantasy XIII won't be released alone. The game is part of the Fabula Nova Crystallis compilation which includes Final Fantasy Versus XIII and Final Fantasy Agito XIII. Even if set in the same world than the 13th episode, Versus XIII has absolutely nothing in common with that game and focalizes on a whole different story with different characters.
Unfortunately, not much has been said about the story or the gameplay. For now, all we know is that the main protagonist is the last heir of the kingdom where the last Crystal is kept. His city has been isolated from the rest of the world and is constantly in battle against another nation for the control of the Crystal.
Concerning the gameplay, Final Fantasy XIII should be closer to a Kingdom Hearts and a Dirge of Cerberus than an actual Final Fantasy episode. In other words, the game should be very action-oriented with elements of a third person shooter. The developers also announced that they would try to make the battles as close as possible as the ones seen in Final Fantasy VII Advent Children which should give incredible fighting sequences. Plus, as seen in the trailer, the main protagonist is able to wield multiple weapons at the same time and move at incredible speeds. Both these elements are sure to be kept in the gameplay.
Announced to be the darkest Final Fantasy episode yet, Final Fantasy Versus XIII is expected as one of the greatest games the PS3 will see. Plus Square Enix has a reputation of giving us amazing intriguing stories and a very well thought gameplay. More information about the game should be revealed at the Tokyo Game Show 2008.