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