Here is the full list of all 28 Vampire's Fall: Origins achievements.
Defeat Arvid Varanger
Defeat Shadow from The Abyss
Defeat Lernaean
Defeat Death's Advocate
Defeat Fulacks the Ugly
Defeat the Hunter Killer
Defeat the Koccuburry Cave Dweller
Find and defeat the three spirit brothers
Defeat the Beast of the Valley
Defeat The Tusk Trio
Find the world cornerstones
Open the seals of Gont
Defeat Vaso
Bite Sava Savanovic
Survive the attack on Vamp'Ire
Refuse to bite Sava Savanovic
Defeat the being in the Rat Tree
Defeat the Mother of Wolves
Defeat Aendisea's Bane
Defeat The Rat King
Defeat Xaphxan The Invisble
Defeat Styx's Servant
Defeat Enigma
Defeat God Brutal of Guard
Defeat God Brutal of The Wild
Defeat God of Brutals
Complete the expansion "The Hunt for Sava"
Complete the brutal mazes