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 Antonia.
Find out about the last story of Eugénie.
Learn all gestures.
Find out about the last story of Sophia.
Collect all special weapons.
[Rise of P] Reach the ending.
Kill the Nameless Puppet.
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.
Decipher all cryptic vessels and claim the rewards.
Find out about the last story of Venigni.
Find out about the last story of Simon Manus.
Kill the Awakened God Simon Manus.
Collect all normal weapons.
Kill Laxasia the Complete.
Strengthen a special weapon to its max level.
Discover all Trinity Sanctums.
Kill the Black Rabbit Brotherhood.
Strengthen a normal weapon to its max level.
Activate P-Organ to Phase 5.
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.
Try to assemble a weapon.
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.
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.