In this walkthrough you can read about good ending. Secret ending is on the second page of this walkthrough.
So, it is necessary to stay out 5 nights.
It is very difficult to fail on the first night. Crawl through the vents. You can use WADS keys to move through ventilation. Your movement will be faster if you press the Shift key. You can see the places where there are animatronics (they are marked with blue and red buttons on the control panel).
Follow the instructions. You need to hide under the table. Grab the door; you will see eyes that will be watching you. Turn away, so as not to look at them. Avoid eye contact with animatronics. Be sure to move the door until it stops to ensure safety.
You will have to use the mouse to keep the vent door closed. Animatronics try to open the door to get you out.
Next is the segment where you want to restore the power supply in each.
Press the Space key to play music. It should play as long as the danger level is green. Next in turn restore the power supply in every room by pressing the reset button.
After power is restored, you head to the elevator to end the second day.
You need to pass through the vent on the right to check Funtime Foxy. You don’t have a flashlight like another vent. You listen to the voice, and return back.
You need to move forward towards the door when a flash of light is appeared. Be careful and stop movement when Foxy next you. When you get to the doll, click on the button to open Freddy.
First, click on the button at the right and left cheek, over his right eye, and then on the nose.
Press 4 or 5 buttons in the upper jaw, and then press the button under the lower jaw. Inside will be a bomb, press the button.
It is necessary to restore the backup power supply. Module from Bowtie Puppet. As soon as you see it, you will have a few seconds to click on it. Go to vent. It will be a little scary.