Key Items are essential for story progression and unlocking new areas. These include the Crystal Stars, the various parts of the Sun and Moon Stones, and specific quest items like Flurrie's Necklace. Unlike consumables, key items are not used up. Collectibles like Star Pieces and Shine Sprites are optional but highly recommended. Star Pieces are traded for badges, while Shine Sprites are used to upgrade your partners. Keep an eye out for these hidden treasures as you explore, as they significantly enhance your power and customization options.
