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