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