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