Here is the full list of all 49 Utawarerumono: Prelude to the Fallen achievements.
Obtained all achievements.
Listened to every BGM.
Viewed all event scenes.
Completed Where the Wild Things March.
Used every main character's co-op chain.
Used every main character's final strike.
Completely filled out the encyclopedia.
Reached the ending.
Completed Great Seal - Part 2.
Completed Demander of Power.
Completed Primordial Dream - Part 2.
Acquired all rewards from training.
Completed all training battles.
Completed Kuuya.
Completed Mask.
Completed The Fallen.
Completed Burning Prison.
Completed Abh-kamu.
Completed Hunter & Hunted - Part 2.
Completed Hansana Offense & Defense.
Completed The Daybreakers.
Completed Abandoned Feelings.
Completed Princess of a Fallen Empire.
Completed Pursuit.
Completed Karulawaturei.
Completed Infiltration.
Completed Giriyaginan Gladiator.
Dealt 1,800+ damage to a single enemy.
Dealt 750+ damage to a single enemy.
Completed False Truths - Part 2.
Completed Battle to the Death on the Bridge.
Completed Evenkurugan Woman.
Completed Special Attack.
Completed Blocking the Shikeripechim Invasion.
Tried training.
Completed Decisive Battle.
Dealt 300+ damage to a single enemy.
Completed Imperial Capital Invasion.
Completed Nuwangi.
Used a final strike.
Completed Tatokori Gate.
Completed Daughter of the Forest.
Used a co-op chain.
Completed Path of No Return.
Completed Revolt.
Completed Ruler of the Wild Forest.
Tried a free battle.
Completed Uninvited Guests.
Successfully performed a chain attack.