Yep! A prequel game will come out one day! It's in VERY early development because I wanna take my time with the writing as COTD's development was frantic. Also don't worry you're not asking for a lot at all!
Here's a tutorial on how to get the secret ending:
Kill zombie attacking you in the first encounter BUT abandon Rocky. Choose every pessimistic option thereafter. Keep the gun for yourself when prompted. Choose "Only true friends think like you do" when reading the Aug 27 journal entry on the first floor in the right hallway. Run away and abandon Vinnie on the first floor. Choose "I'm sorry for your losses" with Norman in the elevator. Select "Don't get distracted" when examining the office floor window with Norman. Don't attempt to save the secret character. Enter the computer password as normal. Push Norman into danger. You are locked into the secret ending at that point.