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