What counts as FNAF 5

Setting: a former pizza house, long after it stopped serving anyone
Goal: keep the doors shut and get to morning
Controls: mouse - doors, lights, and your own nerve
Rule of thumb: glowing eyes mean move, not look
Cost: free in the browser

Five Nights at Freddy's 5 is a horror game popular with players all over the world. It works your logic and your attention, and it trains your tolerance for stress. Once again you are the night watchman guarding a former pizza house. The place is known for the animatronic toys that used to entertain children. At night these creatures are awake too, so you have to be extremely attentive. You have to lock the doors carefully so as not to let the night monsters out of the building. If you meet something with glowing eyes, get away from it.

Which game is "FNAF 5" anyway

Officially the fifth game in the series is Sister Location, released in 2016
The sixth is Pizzeria Simulator, released free a year later
Because Sister Location was not called "FNAF 5" on the box, the number floats
So a search for FNAF 5 turns up both the official game and fan continuations like this one