Here is the full list of all 45 The Forest achievements. It takes around 50-60 hours to unlock all of the achievements on Windows.
Kill bird with arrow
Use the compass
Cut down 1000 trees
Chop up 50 bodies
Revive 10 co-op players
Finish Game
Collect all cassette tapes!
Eat an enemy
Share a weapon in MP
Craft 10 medicine items
Knock down 6 or more trees with 1 explosive. Alone in Single Player or together in Multiplayer.
Cut down 100 trees
Revive one co-op player
In Single Player, don't kill any cannibals for more than 10 days in a row
Share a food or drink item in MP
Survive 5 nights
Sleep on yacht
Survive 1 night
Sleep with another player (group sleep)
Eat an entire family
Craft all items
Kill all animal types and display heads
Grow all plant types
Play through entire game without killing or eating animals. Alone in Single Player or together in Multiplayer.
Explore all caves
Killed downed enemy with rock
Build a super long wall
Make and wear stealth armour
Kill 6 or more fish with a stick of dynamite. Alone in Single Player or together in Multiplayer.
In Single Player, kill 100 cannibals
Find all missing passengers
Kill shark. Alone in Single Player or together in Multiplayer.
Kill a bunny. Alone in Single Player or together in Multiplayer.
Eat all mushroom types
Pass 50,000 steps
Set off 20 bombs
Repair a shelter
Collect all robot pieces
Catch fish with a trap. Alone in Single Player or together in Multiplayer.