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