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