Here is the full list of all 36 Full Metal Furies achievements.
Unlock every piece of equipment for every Class
Complete the game (true end) on NG+
I always wanted a sibling
Unlock every item in the Treasury
See the World
Defeat Titan King Prometheus
Make a choice
Enter the Cave
Solve the Last Puzzle
Solve the Fourth Puzzle
Complete all Class challenges
Find All Monolith Stones in the Stygian Well
Unlock Cerby
Appease Ferryman Charon
Solve the Fifth Puzzle
Find all Monolith Stones in Tartarus
Destroy the World
Defeat Planetar Cronus
Solve the Third Puzzle
Find all Monolith Stones in the Desert of Atlantis
Defeat Sky Sniper Lelantos
Have 1 point in every skill for 1 Class
Solve the Second Puzzle
Find and translate all Monolith Stones in the Foloi Forest
Master a piece of equipment by reaching its max level
The synopsis looks grim
Defeat Land Fortress Coeus
Air crit an enemy 5 times in a row
Solve the First Puzzle
Crack the code for at least 1 Computer
Find and translate all Monolith Stones in Thessaly
Defeat Wavebreaker Meneotius
Earn 1 level in your equipment
Unlock Go-Cat
Unlock your first piece of equipment
Find your first Monolith Stone