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