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.
Pass 50,000 steps
Cut down 1000 trees
Find all missing passengers
Eat all mushroom types
Build a super long wall
Collect all robot pieces
Craft all items
Kill all animal types and display heads
In Single Player, kill 100 cannibals
Eat an entire family
Repair a shelter
Killed downed enemy with rock
Kill shark. Alone in Single Player or together in Multiplayer.
Catch fish with a trap. Alone in Single Player or together in Multiplayer.
Kill a bunny. Alone in Single Player or together in Multiplayer.
Knock down 6 or more trees with 1 explosive. Alone in Single Player or together in Multiplayer.
Kill 6 or more fish with a stick of dynamite. Alone in Single Player or together in Multiplayer.
Sleep on yacht
Set off 20 bombs
Revive 10 co-op players
Eat an enemy
Finish Game
Grow all plant types
Collect all cassette tapes!
Chop up 50 bodies
Craft 10 medicine items
Kill bird with arrow
In Single Player, don't kill any cannibals for more than 10 days in a row
Cut down 100 trees
Share a weapon in MP
Use the compass
Make and wear stealth armour
Revive one co-op player
Survive 5 nights
Share a food or drink item in MP
Sleep with another player (group sleep)
Survive 1 night
Explore all caves