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