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