Following the exploits of the summoner Yuna and her guardians as they battle an evil immortal enemy known as Sin, Final Fantasy X is the first title in the franchise to appear on the PlayStation 2. As well as being the first Final Fantasy game on PlayStation 2, FFX is the first game in Squaresoft's popular RPG series to feature voiceovers in addition to written text. Character expressiveness reaches new heights with the aid of Squaresoft's "Facial Motion System", adding subtle facial expressions to characters in real-time. New side-quests include the underwater sport of Blitzball, and a monster battle arena. Redesigned fighting system mixes classic Final Fantasy elements with a new "Sphere Grid" system.