Here is the full list of all 40 The Vagrant achievements. It takes around 20-25 hours to unlock all of the achievements on Windows.
Achieve true ending
Unlock all achievements
Unlock all entries in Monsterpedia
Defeat Fallen Kumasith
Failed to defeat Kumasith
Defeat Soulreaper
Achieve normal ending
Clear the game in Hard difficulty
Unlock all entries in Note
Collect 1000000 mana
Acquire all skills
Slay the chicken
Unlock all abilities
Acquire Sword of verum
Explore all areas
Collect 1000000 gold
Defeat Valerie
Acquire all recipes
Failed to defeat Shroom prime
Defeat Shroom prime
Defeat Ground shaker
Stop Soulreaper
Failed to stop Soulreaper
Achieve 999 combos
Achieve 500 combos
Achieve 100 combos
Defeat Santiago
Failed to defeat Santiago
Defeat Headless horseman
Consumed 100 potions in total
Defeat Kumasith
Keep drinking potions
Defeat Maximillian II
Slay 666 monsters
Defeat HMWV
Defeat Esgonian general
Fight Soulreaper
Acquire a max ranked weapon or armour
Acquire a weapon or armour with 4 runestones
Acquire an onion from the chef in Brocley village