Complex sentence: Choosing from three difficulties, the player controls Sekai, who after clashing blades with Kotonoha, attempts to fight off their opponent by pressing any two configurable keys in quick session; in the case of the highest difficulty, a third is also used.
Split into simpler sentences: Choosing from three difficulties, the player controls Sekai, who attempts to fight off Kotonoha by pressing any two configurable keys in quick session. In the case of the highest difficulty, a third is also used.