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