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