Ys: The Oath in Felghana follows the hero Adol Christin and his faithful companion Dogi on a classic role-playing adventure through a fantasy realm of supernatural dangers and opportunities. Players guide the characters from an isometric perspective in action-oriented battle and exploration. In a storyline set a few years after the conclusion of the first two original Ys adventures, the game begins as the duo returns to Dogis hometown of Redmont, where they find an influence of evil has spread across the community from a nearby castle. The play of the game is similar to that of the previous PSP adventure, Ys: The Ark of Napishtim. Players control their characters directly as they run, jump, and wield magic-imbued weapons against villainous enemies and ferocious monsters. The 2010 PSP version of Oath in Felghana is based on the Japanese home computer game of the same title -- itself a remake of the third game in the series, Ys III: Wanderers from Ys. The PSP version of the game uses 3D-modeled characters and settings, and includes new missions and cut-scenes. Established in the mid-80s by Japanese developer Falcom, the Ys series was originally inspired by a legendary city that is said to have sunk into the sea, but has grown through many console and handheld adventures to comprise a deep mythology all its own.