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.
Completed the whole level in one go without swatting any mosquitoes
Found the secret in the engine room
Broke every piece of ice on the way to the letterbox in one go
Successfully lassoed between 25 different attach points without touching the ground
Smashed the coal bucket with the excavator to find the hidden collectible
Removed all thistles in one go
Found the hidden collectible in the kite flying section
Mended a broken bond
Found the other broken half piece
Found a broken half piece
Found the eighth missing piece
Cleared the snow away from all the branches in one go
Found the seventh missing piece
Retrieved the stolen piece
Found the collectible in the crushing, zapping death machine
Found the sixth missing piece
Found the fifth missing piece
Made it to the water wheel without using a log raft
Found the fourth missing piece
Found the secret in the maze section
Found the third missing piece
Found the second missing piece
Found the first missing piece
Collect all Achievements
Find every secret
Finish each level from start to finish without dying