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.
Defeat Nyarlathotep & The Shining Trapezohedron.
Find all Perks.
Destroy seven Elder Shards.
Defeat Nyarlathotep.
Defeat Legion & Salvation.
Defeat all Minibosses.
Unlock all Abilities.
Destroy your first Elder Shard.
Equip three Perks simultaneously.
Defeat Hysteria.
Collect 500,000 Shards.
Defeat Dominion.
Corrupt your first Ability.
Collect 10,000 Shards.
Defeat your first Miniboss.
Equip your first Perk.
Survive your first horde.
Unlock your first Ability.