Here is the full list of all 42 Lies of P achievements. It takes around 60-80 hours to unlock all of the achievements on Windows.
Find out about the last story of Geppetto.
[Real boy: They all lived happily ever after] Reach the ending.
Collect and play all records.
Find out about the last story of Eugénie.
Find out about the last story of Sophia.
[Rise of P] Reach the ending.
Collect all special weapons.
Decipher all cryptic vessels and claim the rewards.
Learn all gestures.
Collect all normal weapons.
Strengthen a normal weapon to its max level.
Collect all Legion Arms.
Play a perfect tune on the piano at Hotel Krat.
[Free from the puppet string] Reach the ending.
Kill the Nameless Puppet.
Find out about the last story of Simon Manus.
Kill the Awakened God Simon Manus.
Kill Laxasia the Complete.
Find out about the last story of Antonia.
Strengthen a special weapon to its max level.
Find out about the last story of Venigni.
Discover all Trinity Sanctums.
Kill the Black Rabbit Brotherhood.
Activate P-Organ to Phase 5.
Kill the Corrupted Parade Master.
Modify a Legion Arm to its max level.
Kill the Puppet-Devouring Green Monster.
Kill Champion Victor.
Kill all types of Dimensional Butterflies.
Kill Romeo, King of Puppets.
Harvest Gold Coin Fruit.
Kill the Eldest of the Black Rabbit Brotherhood.
Destroy an enemy’s weapon with a perfect guard.
Kill the Fallen Archbishop Andreus.
Try to assemble a weapon.
Kill King’s Flame, Fuoco.
Kill the Scrapped Watchman.
Kill a Stalker.
Tell a lie in front of Hotel Krat Entrance.
Kill the Parade Master.
Repair a Stargazer.
Deliver a successful Fatal Attack.