Kingdom Hearts II/Atlantica

Overview: this world is very different than others. All scenes are music sequences.

Chapter 1: Swim This Way

 * Unlock: Default

Chapter 2: Part of Your World

 * Unlock: Defeat Oogie Boogie in Halloween Town

Chapter 3: Under the Sea

 * Unlock: Defeat the Hostile Program in Space Paranoids

Chapter 4: Ursula's Revenge

 * Unlock: Defeat the Grim Reaper in Port Royal (second battle)

Chapter 5: A New Day is Dawning

 * Unlock: Defeat the Groundshaker in the Pride Lands