Hi everyone, I've just unlocked Golden Freddy Mode!
Full Disclosure: I have personally only beaten this mode on Easy, Normal, and Hard (which was no small task). However, I haven't even made it to 2 am on Very Hard, and only made it past 1 am a couple of times. So with that in mind, don't view it as something that is required to "finish" the game. It's there for people who want to try the impossible and see how long they can last! :)
Enjoy!