Kingdom Hearts: Chain of Memories delivers an entirely new adventure and sets the stage for Kingdom Hearts II. Sora wanders into a castle where he and his companions, Donald and Goofy, realize their magic and skills, earned in the first game, have been completely stripped away. Sora must traverse the castle on his own this time. Donald and Goofy must stay behind, but they'll accommodate Sora during battles as special attack "cards.”. It's up to players to battle enemies to collect cards that'll unlock doors to the next part of the map.