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