It's called Soulcalibur Lost Swords, and it will be a PlayStation 3 exclusive. The newest entry to the Soulcalibur fighting game series, apart from being free-to-play, will feature a new "item discovery and forging" system for its weapons, along with elemental-based (fire, wind, etc) fighting mechanics.
Lost Swords will be a singleplayer game with a mission-based campaign. Namco-Bandai stated that while they will release DLC for Lost Swords, they will not be required to complete the game and only offer "more choices" to players.
Soulcalibur Lost Swords arrives in the West later this year, with the Japanese version launching "soon".