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