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