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