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