Please note: all credit goes to Skulky_!
Here i’ll show you how to unlock the Secret Ending and get the Avid Worker achievement!
How to Obtain Avid Worker Achievement (Secret Ending)
To get the Secret Ending you have to start a new game and watch the cutscene.
When your sitting at the desk don’t press E to stand up.
Just wait there it takes 20 minutes but its worth the achievement.
Eventually Audrey will say something then the screen will turn black and you will get the Avid Worker achievement and the Secret Ending.
I hope this helped!