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