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