Here is the full list of all 50 11-11 Memories Retold achievements. It takes around 15-20 hours to unlock all of the achievements on Windows.
Unlock the peace ending
Unlock the grudge ending
Unlock the forgiven ending
Unlock the betrayal ending
Unlock the lone avenger ending
Find all the collectibles
Find all the collectibles from Part III
Go home to Julia
Take a photo of the rifle on Kurt's kitchen wall in "The Pursuit", fire the same gun in "Peace"
Unlock the sacrifice ending
Listen to Barrett's tearful account of the lives lost under his command
Threaten the soldier three times to learn the truth
Take all the apples back to Lucie
Win at card game against the old ladies in the village.
Win all card games
Find all the collectibles from Part II
Help Daniel in Passchendaele
As Lotty, comfort the soldier under the tree
Catch a rat in the tunnels
Purr with Lotty
Save Lothar
Find all the collectibles from Part I
Bring all four wood pieces to the oven
Give some chocolate to a german soldier
Score with the hidden football in Paris
Finish Vimy battle without dying
Take a picture of Lotty in Vimy trenches
Collide with 20 ghosts or more
Don't collide with any ghosts
See all the credits
Complete Part III
Unlock the revenge ending
Choose to go and save Kurt
Use all your photographic film in one chapter
Kick the football in the POW camp
Complete Part II
Get out of the church of Passchendaele
Cut the gas in Passchendaele
Cut the german communication
Find all missing boys from your village.
Perform all moves in the Dance sequence
Pull the cart of crosses in the cemetery
Find the hidden food stash in the tunnels
Take a picture of Kurt in "The Collapse"
Complete Part I
Do business with Joe
Send two pictures to Julia
Use one of the lifts on Vimy Ridge
Avoid all the mines
Explore Julia's Room