Here is the full list of all 28 Unravel Two achievements.
Complete all of the bonus levels in under 45 minutes in one go
Earn the gold medal in Hideaway
Earn the gold medal in Little frogs
Complete any bonus level
Earn the gold medal in Nightswimming
Complete At the rapids in one go without dying
Earn the gold medal in At the rapids
Complete a level in co-op
Travel from the island with the tables back up to the lifebuoy in At the rapids
Travel between the two barrels in At the rapids without touching the water
Earn the gold medal in Ashes to ashes
Complete Ashes to ashes in one go without dying
Make it between the two moose signs in Ashes to ashes without using any directional inputs
Complete Is that all there is in one go without dying
Earn the gold medal in Is that all there is
Complete Nightswimming in one go without dying
Survive 5 pike attacks in a row without using your lasso in the pike chase
Complete Little frogs in one go without dying
Complete Hideaway in one go without dying
Complete At the rapids
Complete Ashes to ashes
Complete Is that all there is
Complete Nightswimming
Complete Little frogs
Complete Hideaway
Earn a medal for achieving a time or not dying on any level
Customise a character
Complete Foreign shore