Here is the full list of all 43 Fuga: Melodies of Steel achievements.
Cleared Chapter 3.
Succeeded at the laundry.
Relieved status ailments by sleeping in the dormitory.
Delayed the enemy 100 times.
Won an elite battle.
Expanded a facility.
Went exploring.
Cleared Chapter 2.
Harvested the farm.
Raised affinity to level 3 with an ally.
Cleared Chapter 1.
Used a link attack.
Succeeded at cooking.
Succeeded at scrap fishing.
Successfully made an upgrade.
Won a battle.
Cleared Chapter 4.
Cleared Chapter 5.
Cleared Chapter 6.
Cleared Chapter 7.
Cleared Chapter 8.
Cleared Chapter 9.
Cleared Chapter 10.
Cleared Chapter 11.
Cleared Chapter 12.
Defeated the final boss with 12 surviving children.
Attained S rank in battle 50 times.
Won 10 elite battles.
Reached level 50 with a character.
Reached level 50 with all characters.
Fully upgraded something.
Scrap fished 50 times.
Harvested 200 items from the farm.
Expanded all facilities to the max level.
Obtained information on 30 locations from the observation room.
Reached level 25 with a character.
Attained S rank in exploration 10 times.
Obtained all comic pages.
Saved a friend in despair in Chapter 11.
Revitalized a depressed ally.
Raised affinity to level 10 with an ally.
Raised affinity to level 10 with 30 pairs.
Unlocked all achievements.