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