Here is the full list of all 36 Valkyria Chronicles 4 achievements. It takes around 60-80 hours to unlock all of the achievements on Windows.
Obtained all achievements.
Obtained all decorations.
Watched all event scenes.
Obtained A ranks on all missions.
Triggered a Last Stand 15 times.
Obtained all infantry weapons.
Recruited all squad members.
Obtained all tank parts.
Gave ship orders 15 times.
Completed a squad story for the first time.
Obtained all ship parts.
Defeated 1000 enemy units.
Obtained A ranks on 20 missions.
Rescued 10 allies in critical condition.
Kept your promise with Riley Miller.
All of your classes were upgraded to max level.
One of your classes was promoted to Paragon status.
Learned all orders.
Completed Chapter 18, and ended Belgar's dark ambitions.
Completed Chapter 17, and witnessed the end of the war.
Defeated 15 enemy aces.
Completed Chapter 15, and defeated both Walz and Crymaria.
Gave orders 15 times.
Earned 1,000,000 DCT cumulatively.
Completed Chapter 11, and made it past the Sea Fortress.
One of your classes was promoted to Elite status.
Developed the Hafen into a heavy tank.
Completed Chapter 7, and rendezvoused with the Centurion.
Completed 10 missions without anyone in critical condition.
Gave direct commands 15 times.
Completed Chapter 4, and won the battle of Siegval.
One of your squadmates was promoted to Corporal.
Defeated an enemy ace for the first time.
Learned an order at the Mess Hall for the first time.
Used R&D Facility for the first time.
Obtained an A rank on a mission for the first time.