When you have completed the game save the data when you are prompted and load that file to start a new game. In the new game you will have retained Party Levels, Score Pieces and a Hero's Crest from the saved file. ALL the enemies and bosses will be harder to defeat in this new game.

Complete the following tasks to unlock the corresponding GamerScore. Due to some of these achievements being story related they can only be unlocked while playing the Encore which may result in spoilers.

Party Level 2 - GamerScore 10:
Get party level 2.

Party Level 3 - GamerScore 10:
Get party level 3.

Party Level 4 - GamerScore 10:
Get party level 4.

Party Level 5 - GamerScore 10:
Get party level 5.

Party Level 6 - GamerScore 20:
Get party level 6.

Raindrops - GamerScore 10:
Complete chapter 1.

Revolution - GamerScore 10:
Complete chapter 2.

Fantaisie Impromptu - GamerScore 10:
Complete chapter 3.

Grande Valse Brilliante - GamerScore 10:
Complete chapter 4.

Nocturne - GamerScore 10:
Complete chapter 5.

Tristesse - GamerScore 10:
Complete Chapter 6.

Heroic - GamerScore 10:
Complete chapter 7.

Heaven's Mirror - GamerScore 10:
Complete Final Chapter: Heaven's Mirror.

Hero's Gate - GamerScore 30:
Open the way to Mysterious Unison Using the Hero's Crest.

Claves's Resurrection - GamerScore 50:
Collect ALL 7 pieces of Claves's Soul.

Rondo's Return - GamerScore 50:
In Mysterious Unison defeat Rondo.

Grand Finale - GamerScore 70:
Unlock Claves and defeat Frederic.

Soul Released - GamerScore 79:
Free Chord's Soul from Fort Fermata.

Pirate's Treasure - GamerScore 80:
Get Dolce's treasure.

Xylophone Treasure - GamerScore 80:
Open the secret door in Xylophone Tower Using your orb.

Score Piece Collector - GamerScore 100:
Collect ALL 32 Score Pieces.

EZI Worshipper - GamerScore 321:
Collect ALL the EZI items in the game.