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