Here is the full list of all 39 Achilles: Legends Untold achievements.
Kill your first opponent
Face Paris
Find the blacksmith
Unlock the armor with the scorpion theme
Defeat Agamemnon
See Hades in his true form
Defeat the Minotaur
Defeat Tydeus
Defeat the Chimera
Unlock the armor with the Zeus theme
Defeat Phobos
Start a new game with New Game+
Defeat Paris
Find the hidden path
Survive the cultist ambush without receiving a negative curse status
Defeat the bronze statue
Finish the game as a human
Finish the game as a hero
Finish the game with the Hero difficulty settings
Die for the first time. Get used to it.
Purchase the first skill on the skill tree
Upgrade your weapon or armor for the first time
Finish the game, sparing all the bosses when given the choice
Finish the game, not sparing any of the bosses when given the choice
Unlock all the shrines
Visit every cellar and ruins available in the game
Upgrade your weapon or armor to the maximum level
Defeat an enemy while having all possible negative statuses
Destroy 1,000 destructible elements
Kick your opponents 300 times
Perform 50 counterattacks
Defeat 20 opponents with a shield throw
Defeat 500 archers
Get all the notes
Open every runic chest
Send off all the soldiers’ souls
Defeat all the Laestrygonians
Release all the prisoners from the cages
Destroy all cursed masks