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