Here is the full list of all 44 Vagante achievements.
Beat the Game without All Rune Orbs
Beat the Game with All Rune Orbs
Complete the Rifts
Kill the Rust Fiend
Kill the Tower Serpent
Kill the Behemoth
Kill the Shadow Knight
Kill the Chimera
Complete the Catacombs
Kill the Abomination
Kill the Necromancer
Kill the Zombie Dragon
Kill the Evil Mage
Complete the Forest
Kill the Vine Lord
Kill the Mushroom Golem
Kill the Wisp Queen
Complete the Caves
Kill the Baby Dragon
Kill the Rock Worm
Kill the Goblin King
Kill the Brood Demon
Beat the Caves on Hard
Beat the Forest on Hard
Beat the Catacombs on Hard
Beat the Rift on Hard
Beat the Game without All Rune Orbs on Hard
Beat the Game with All Rune Orbs on Hard
Kill the Chimera on Hard
Kill the Tower Serpent on Hard
Kill the Rust Fiend on Hard
Kill the Baby Dragon on Hard
Kill the Rock Worm on Hard
Kill the Goblin King on Hard
Kill the Mushroom Golem on Hard
Kill the Wisp Queen on Hard
Kill the Vine Lord on Hard
Kill the Abomination on Hard
Kill the Necromancer on Hard
Kill the Zombie Dragon on Hard
Kill the Behemoth on Hard
Kill the Shadow Knight on Hard
Kill the Brood Demon on Hard