Here is the full list of all 63 Neon White achievements.
Collect all gifts
Complete 100% of the game
Earn an Ace medal on every level
Unlock one last memory
Restore Heaven
Complete Mission 12
Write Green into the Book of Life
Defeat Green at the Hand of God
Complete Mission 11
Complete your relationship with Mikey
Unlock all of White's memories
Complete your relationship with Red
Complete Red's Sidequests
Complete your relationship with Raz
Complete your relationship with Violet
Complete your relationship with Yellow
Complete your relationship with Green
Use the Book of Life Card on a Mimic
Redeem every Heavenly Delight Ticket
Complete Mission 10
Defeat Green at the Third Temple
Complete Violet's Sidequests
Complete Yellow's Sidequests
Complete Mission 9
Complete Mission 8
Complete Mission 7
Find a Strange Coin
Die from a Mimic's bullet
Complete Mission 6
Collect 50% of the total gifts
Earn 50% of the total Ace medals
Get killed by a Tripwire
Unlock one of Red's memories
Unlock one of Violet's memories
Unlock one of Yellow's memories
Complete Mission 5
Complete Mission 4
Defeat Green at the Clocktower
Collect ten cards from vending machines
Complete Mission 3
Stomp off of the edge of a level
Complete Mission 2
Deplete the Fists card
Redeem a Heavenly Delight Ticket
Use the Fists card
Give your first gift
Complete Mission 1
Kill an enemy by parrying a bullet at them using the Katana card
Earn your first Ace medal
Defeat Green at the Clocktower before he reaches the top floor
Defeat Green at the Third Temple before he reaches the final stage
Write Green into the Book of Death
Complete White's Heaven Rush
Complete White's Hell Rush
Complete Red's Heaven Rush
Complete Red's Hell Rush
Complete Violet's Heaven Rush
Complete Violet's Hell Rush
Complete Yellow's Heaven Rush
Complete Yellow's Hell Rush
Complete Mikey's Heaven Rush
Complete Mikey's Hell Rush
Discovered Idiot Island