Key items are unique, non-consumable items that are often required for story progression or unlocking new areas. These include items like the 'Tome of Order', 'Magic Seal', and various keys. Relics, as mentioned previously, grant permanent abilities or passive bonuses, such as 'Double Jump', 'High Jump', 'Slide', and 'Merman Statue' (allowing underwater breathing). Unlike consumables, key items and relics are permanently added to your inventory once acquired. Always check your key items list if you're stuck, as a specific item might be needed to open a path or solve a puzzle. Many relics are found after defeating bosses or in hidden rooms.
