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.
[Free from the puppet string] Reach the ending.
Find out about the last story of Geppetto.
[Real boy: They all lived happily ever after] Reach the ending.
Collect and play all records.
Decipher all cryptic vessels and claim the rewards.
Collect all normal weapons.
Discover all Trinity Sanctums.
Collect all special weapons.
Learn all gestures.
Find out about the last story of Sophia.
Play a perfect tune on the piano at Hotel Krat.
[Rise of P] Reach the ending.
Kill the Nameless Puppet.
Find out about the last story of Simon Manus.
Kill the Awakened God Simon Manus.
Find out about the last story of Antonia.
Kill Laxasia the Complete.
Strengthen a special weapon to its max level.
Find out about the last story of Venigni.
Find out about the last story of Eugénie.
Kill the Black Rabbit Brotherhood.
Strengthen a normal weapon to its max level.
Kill the Corrupted Parade Master.
Activate P-Organ to Phase 5.
Collect all Legion Arms.
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.
Try to assemble a weapon.
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.
Destroy an enemy’s weapon with a perfect guard.