Here is the full list of all 20 Heroes of Arca achievements.
Heal 2500 health points.
Win 3 battles taking no damage.
Learn Double Attack, Heal and Sacrifice skills.
Win a battle in 4 turns.
Pass all parts of the tutorial
Win 100 fights.
Lose 50 fights.
Gather 25 artifacts.
Get aboard a ship. Sail to the desert. Sail to the Major Land.
Inflict 2000 damage with Destruction.
Inflict 1500 damage with Explosion.
Stun 100 enemies.
Find all parts of the Ancients' key.
Reach 40th level.
Destroy 30 Pisces.
Summon 500 creatures.
Block 20000 damage with Defensive Barrier.
Defeat all Key Wardens.
Discover 1st, 2nd, 3rd piece of history of Arca.
Destroy all Faceless.