Here is the full list of all 12 Fe achievements.
Unlock all abilities
Find all Silent Helmets
Glide from the top of the waterfall all the way to the marsh
Free an old friend
Complete the game
Find all the Fe playing hide & seek
Gather 10 or more lizards for a conversation
Jump from one owl's back to another
Jump between 10 different trees without touching the ground
Lead a bear to a Silent camp
Find your first Silent Helmet
Learn to climb trees