The demo version of Final Fantasy XIII will be included with the Blu-Ray release of Square's computer-generated film, Final Fantasy VII: Advent Children. As often happens with eagerly anticipated releases, some wily Japanese gamers got their hands on the demo early and leaked videos onto YouTube.

Final Fantasy 13 is the first installment of a planned trilogy of games, each of which will involve different characters and worlds in the same universe.IGN: E3 2006: Eyes-on Final Fantasy XIII Trailer(May 8, 2006)

The story centers around the fal'Cie, a mystical non-human race, who mark people destined for a greater purpose. These people are called l'Cie. Several centuries ago, the fal'Cie constructed a paradise city in the sky called Cocoon. The world below, which is known as Pulse, has grown into a frightening wilderness inhabited by monsters and has a strange effect on humans. Ever cautious, the people of Cocoon exile anyone who has come under the influence of Pulse.

One of FFXIII's main characters, Lightning, is designated a l'Cie by the fal'Cie. Unsure of her past or even her real name, Lightning finds herself destined to become an enemy to humanity who will bring about the downfall of Cocoon.IGN: Final Fantasy XIII Update (January 10, 2007)

• GameSpot: Final Fantasy XIII Demo Walkthrough Part 1: Lightning and Sazh (Time: 29:08)

• GameSpot: Final Fantasy XIII Demo Walkthrough Part 2: Team Nora & Big Boss Battle (Time: 19:54)

• Destructoid: Preview: Final Fantasy XIII Japanese demo (April 24, 2009)