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