Here is the full list of all 38 Thymesia achievements.
Break 1000 barrels.
Unlock all achievements.
Empty the first health bar of Varg in the tutorial.
Reach the "Power of Cleasing" ending.
Reach all endings.
Collect all story bits.
Collect all entries in the collection.
Reach max level.
Reach the "Harmonized Force" ending.
Collect all lore.
Reach the "Blessing of Pure Blood" ending.
Reach the "Power of Vile Blood" ending.
Reach the "Chaotic Power" ending.
Finish all levels.
Defeat Corvus.
Craft all potion recipes.
Collect all potion ingredients.
Craft a potion recipe for the first time
Unlock all plague weapons.
Defeat Urd.
Defeat Mutated Odur.
Finish "Hermes Fortress" level.
Defeat Varg.
Fully upgrade a plague weapon for the first time.
Defeat Sound of the Abyss.
Fully upgrade a potion.
Defeat God of the Fools.
Defeat any boss without using potion.
Finish "Royal Garden" level.
Defeat The Hanged Queen.
Finish "Sea of Trees" level.
Defeat Odur.
Unlock a plague weapon for the first time.
Start recalling for the first time.
Finish the tutorial.
Dead for the first time.
Rest at the beacon for the first time.
Reave a plague weapon for the first time.