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