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