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