Here is the full list of all 12 Brothers: A Tale of Two Sons achievements worth 1,000 gamerscore.
Take a break from adventuring.
Throw someone's ball down a well.
Every family's got one.
Make the bunnies play nice.
Make someone feel better.
Re-unite the two love birds.
Make the inventor dance.
Sound the giant horn.
Find the secret.
Help the turtles to the sea.
Practise singing.
Make a wish.