In a recent interview with Famitsu, director Hajime Tabata revealed that Final Fantasy XV will be 15 chapters long. If you just stick to just the main story, you can expect to have somewhere between 40 and 50 hours of playtime. The first half of which will be an open world structure, while the second half will be more linear and story driven. The reason for this is to help players not get exhausted by the open world aspects, and to give players a more traditional Final Fantasy experience. Tabata also revealed that the game is currently 90% complete.
Final Fantasy XV is currently set to release on November 29, 2016 for both PlayStation 4 and Xbox One
