Here is the full list of all 20 Sundered achievements. It takes around 25-30 hours to unlock all of the achievements on Windows.
Defeat Humanity.
Corrupt seven Abilities.
Corrupt your first Ability.
Defeat Nyarlathotep & The Shining Trapezohedron.
Collect 500,000 Shards.
Destroy seven Elder Shards.
Defeat Nyarlathotep.
Destroy your first Elder Shard.
Defeat Legion & Salvation.
Find all Perks.
Defeat all Minibosses.
Unlock all Abilities.
Equip three Perks simultaneously.
Defeat Hysteria.
Defeat Dominion.
Collect 10,000 Shards.
Survive your first horde.
Defeat your first Miniboss.
Equip your first Perk.
Unlock your first Ability.