Here is the full list of all 30 Downward achievements.
Unlock all Wisdom skills.
Buy all the upgrades of the Old Man's Room.
Obtain 500 Skypieces.
Sell 15 items to the Merchant.
Unlock all Pursuance skills.
Die from a Drone explosion.
Perform 500 wall-jumps.
Obtain the Slingshot Artifact.
Gather 50 Dry Artifacts.
Reach the temple on top of the cliff.
Unlock all Insight skills.
Gather 25 Dry Artifacts.
Obtain the Double Jump Artifact.
Sell 5 items to the Merchant.
Exit the tutorial area.
Defeat your first golem.
Use the Mark for the first time.
Wake Up!
Obtain 1000 Skypieces.
Obtain 2000 Skypieces.
Get a Gold medal in the Challenges.
Get 10 Gold medals in the Challenges.
Perform 500 wall-runs.
Perform 500 double jumps.
Perform 500 slingshots.
Unlock all Endurance skills.
Unlock all Meditation skills.
Survive your own recklessness.
Build four different rooms in the Merchant's Lair.
Die from a Cactus.