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