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