Ys IV - Mask of the Sun is an action-RPG game developed by FromSoftware and published by Bandai Namco. It was released in Japan on October 15, 1998, and in North America and Europe on November 3, 1998. It is the fourth game in the Ys series, and the fifteenth game overall. The game is set in the world of Ys, which is a parallel world to our own. In Ys IV, the player takes control of a young boy named Ein, who is journeying through the world in search of a mask that can stop the sun from setting. Along the way, the player must avoid enemies, solve puzzles, and find treasure to help Ein. The game is set in a 3D environment, and it features a variety of different enemies and environments. The player can also use a variety of weapons, including a bow and arrow, a sword, and a shield.