Here is the full list of all 53 Beyond the Long Night achievements.
Find Archie after they fail to escape to the Overworld
Beat a run using your main bullets weapon 100 times or less
Beat an encore run in the iron hat
Beat a run in the iron hat
Discover all of the old diary entries
Beat a run in under 25 minutes without taking any damage
Find the remains of Archie after they escape to the Overworld
Find Tetchy's remains after they escape to the Overworld
Find the Annoying Child awake in the Strange Dimension
Escape the Long Night
Defeat Sara
Discover the secret combination within the strange dimension
Reach the strange dimension
Discover all three runes in the monuments
Beat a run without using your Superpower
Beat a run without collecting any upgrades
Beat a run having visited every room on the map
Learn everything you can from Archie
Beat an encore run in the mushroom hat
Beat a run in the mushroom hat
Discover the invisible gate in the Sanctuary
Give the Annoying Child enough shiny stones to make a golden bust of themselves
Find one of the old diary entries
Discover the Ear Horn
Beat an encore run in the explorer hat
Escort Tetchy and Dopey to the Sanctuary
Engrave all of the cow statues
Beat an encore run in the party hat
Beat a run in under 25 minutes
Find the Pilgrim after they leave the altar room
Beat a run in the party hat
Meet Umpa
Discover every Upgrade and Superpower in the game
Get the annoying child to recognise you after you return from the Overworld
Speak to Pickles after returning from the Overworld
Beat a run in the explorer hat
Open all of the Annoying Child's shops
Reach the Sanctuary
Choose every type of stone at the monuments
Reach Hope's Peak
Meet Tetchy and Dopey
Meet the Pilgrim
Engrave a cow statue
Meet Archie
Reach the Forbidden Temple
Meet Sara
Discover the Storm
Meet the Annoying Child
Return to the farm after the cows escape
Return to the Dark Mountain after your first death.
Meet Bobbins
Meet Eebi
Meet Pickles