Visit the postgame room.
Finish the epilogue.
Finish the game.
Enter the core of Sephonie Island.
Reach the depths of Layer 2.
Reach the depths of Layer 3.
Reach the depths of Layer 1.
Get the Return to Surface ability.
Find 20 non-key items.
Link with Pomelia.
Link with 10 non-key creatures
Link with Thraskias.
Enter the first layer of the caves.
Link with a species on the surface.
Link with a Coral.