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