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