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