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