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