Even though the game is in a very early stage, I would like to suggest some additions /changes for a more user friendly experience.
The camera button at the bottom seems too wide as it may be accidentally hovered over, and therefore pulled down, whilst trying to select different cameras. I suggest making it a bit more narrow or moving the map further up the screen.
The buttons to select each camera seem quite small which could potentially cause problems, especially in later nights. So perhaps making the buttons larger is a good idea.
The night is quite long, being around 9 minutes and although I can understand you may want to be accurate to FNAF 1, 9 minutes is a very long time. Even Scott understood that, making the nights in FNAF 2 through FNAF SL around 6 minutes. If you do not intend to make the game a grueling experience, I suggest shortening the nights.
Also I am not sure if this is intentional but, Mangle can enter your office and will only attack you if you pull up your camera. Therefore, you could start the night, do nothing and still end up getting to 6AM.
These are just my suggestions/concerns and I look forward to seeing where this project heads in the future.