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