Here is the full list of all 23 Still There achievements.
Begin Chapter One
Begin Chapter Two
Begin Chapter Three
Begin Chapter Four
Begin Chapter Five
Begin Final Chapter
Complete the game
Watch the credits
Decode the mysterious signal
Fix the Cooling System
Hide the Bento
Fix the oxygen leakage
Restore the electricity supply
Give a funeral to your little friend
Take Gorky out with you
Win a chess match with Gorky
Take care of the tuatara
Eat milk
Drink coffee
Drink five coffees
Open the menu during fake credits
Draw a tally mark for each day on the Bento
Wash your teeth