Here is the full list of all 35 Little Nightmares II achievements. It takes around 8-10 hours to unlock all of the achievements on Windows.
Your life is now free of challenges. Congratulations
Nothing of us remains in the wilderness
Nothing of us remains anywhere. Bravo!
Perfect! It's so... you!
It's all over now
Hats are very important to some people
There, you'll be much warmer now
Life in the big city is all over
You punctuated someone's day. Maybe they'll notice!
Hello, have we met?
Nothing of us remains in the pale city
Are you sure you don't need any further... treatments?
It's crueller to let him live
It would be cliché to collect them all
Any other last requests?
Nothing of us remains in the hospital
Some holes are more picky than others
Movie night on the ward - all taken care of!
Better to be safe than sorry
I see through you...
Plenty of snacks for a growing boy
Best days of our short, terrible life
You never know when you need protection from the elements
Nothing of us remains at the school
My, what a curious song you play!
Tempting, so tempting...
Creative, efficient, brutal. Top of the class!
Relax, she heard you!
Hold tight and we'll be just fine
Rebellion at its finest!
Unorthodox, but they all count!
Nature is a terrifying thing
It's not murder if they're bad people... is it?
What did you expect to see in there?
Not today!