Asagi War mode preview
Press Triangle, Square, X, Triangle, Square, X, Circle at the title screen.
Bonus levels
Collect the indicated number of Lucky Dolls, then talk to the Lucky Doll NPC to unlock the corresponding level.
Baal Tower: 70 Lucky Dolls. This level is accessed by the Dimension Guide.
Etna Boss Battle: 100 Lucky Dolls. This level is accessible from Etna's chamber
Overlord Priere Stage: 36 Lucky Dolls. This level is accessed by the Dimension Guide.