Ys IV: Mask of the Sun: A New Theory is a PlayStation 2 action role-playing game and a remake of the Super Famicom title Ys IV. The game retains the original narrative while introducing a revamped combat system that utilizes a traditional button-based control scheme, moving away from the original bump combat mechanic where players collided with enemies.
Ys IV: Mask of the Sun - A New Theory is a remake of the original Ys IV for the Super Famicom. It follows the story of the original, but revamps the combat to be based on a more traditional button-press system than the original game's `bump` combat, based on running into enemies off-center.