Here is an overview of the game, via Bandai Namco:
Sword Art Online: Integral Factor features original and exclusive stories with all-new plot twists, new characters and monsters, as well as familiar faces returning from the beloved series, including Kirito and Asuna.
To celebrate the launch of Sword Art Online: Integral Factor, all users who download the game by Wednesday, May 9 will receive 2,500 Arcana Gems, two types of in-game stamps, original avatars and a 4-star Asuna Skill Record. Log in now to receive your bonuses and get a head start on Sword Art Online: Integral Factor.
Set in the virtual world of Sword Art Online, players will battle to escape the deadly game world by becoming the hero within the enormous realm. In Sword Art Online: Integral Factor, the users transform into one of the players trapped in a deadly game, and they must team up with a new partner, Koharu, to form an Assault Team to destroy powerful monsters, clear difficult quests and conquer Aincrad.
Fans of the Sword Art Online light novel series, can also read a special comic prologue introducing Sword Art Online: Integral Factor’s new protagonist and partner Koharu, and explaining how the two ended up in the deadly game. The prologue for the game is available now for free on the Sword Art Online: Integral Factor official page.