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