Here is the full list of all 14 Harmonia achievements.
Used the Gallery Mode
Used the Music Mode
You can now skip in-game text by pressing the Control key
Completed Harmonia
Chapter 8: World in Harmony Cleared
Chapter 7: Warm Memories Cleared
Chapter 6: Assault Cleared
Chapter 5: Blue Little Lady Cleared
Chapter 4: End of Sorrow Cleared
Chapter 3: Liberation of the Heart Cleared
Chapter 2: Connection Cleared
Chapter 1: Encounter Cleared
Chapter 0: The First Tone Cleared
Started the game for the first time