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