Here is the full list of all 26 Unravel achievements worth 1,000 gamerscore. It takes around 12-15 hours to unlock all of the achievements on Xbox One.
Retrieved the stolen piece
Found the collectible in the crushing, zapping death machine
Found the sixth missing piece
Smashed the coal bucket with the excavator to find the hidden collectible
Found the fifth missing piece
Found the fourth missing piece
Found the secret in the maze section
Completed the whole level in one go without swatting any mosquitoes
Found the third missing piece
Found the second missing piece
Found the hidden collectible in the kite flying section
Removed all thistles in one go
Found the first missing piece
Collect all Achievements
Mend a broken bond
Find every secret
Finish each level from start to finish without dying
Find the seventh missing piece
Find the eighth missing piece
Find a broken half piece
Find the other broken half piece
Make it to the water wheel without using a log raft
Break all the ice on the way to the letterbox in one go
Clear all the snowy branches in one go
Find the secret in the engine room
Use your lasso to jump between 25 different points without touching the ground