This game is actually scarier than the first but it suffers from mechanical issues.
For the scare factor I think the emphasis on keeping track of one animatronic does wonders, as opposed to FNaF 1 or FNaF 2 where your role is passive (waiting for things to show up and dealing with them) here you have to actively be tracking down Springtrap and luring him as far away as possible. The consequences of this are as soon as you lose him for just a second (which is easy to do, he really blends into the cameras) panic mode is instantly initiated at full blast. This is made even WORSE by your systems failing, taking away your only lines of defense and the wait you have to sit through for them to fix is agonizingly tense.
Sadly, despite its horror factor, this game suffers from gameplay issues. Since Springtrap is the only animatronic if he doesn't act aggressive enough you pretty much instantly win, unlike in other games where even if one wasn't being aggressive the others would make up for it. The reverse of this is also true, since Springtrap is the only threat here he's more dangerous than the ones before in other games, so if he decides to be super aggressive then you're going to be having a bad time. Still though I don't think this game ever outright decides you lose like FNaF 2 does, so that's a plus. Most of the Phantoms barely ever show up, BB, Foxy, and Freddy are the only ones you'll consistently have to deal with which sucks since that's only half of them. Additionally one of the phantoms (Puppet) is so terrible that if you get caught by them your run is basically over. The way to get the true ending isn't intuitive at all and was designed 100% with internet guides in mind, I don't think that's very good design.
If you enjoyed any of the other FNaF games give this one a go, it's definitely one of the best FNaF has to offer and because of that is also a decent one to play if you just want to get into the series.
For the scare factor I think the emphasis on keeping track of one animatronic does wonders, as opposed to FNaF 1 or FNaF 2 where your role is passive (waiting for things to show up and dealing with them) here you have to actively be tracking down Springtrap and luring him as far away as possible. The consequences of this are as soon as you lose him for just a second (which is easy to do, he really blends into the cameras) panic mode is instantly initiated at full blast. This is made even WORSE by your systems failing, taking away your only lines of defense and the wait you have to sit through for them to fix is agonizingly tense.
Sadly, despite its horror factor, this game suffers from gameplay issues. Since Springtrap is the only animatronic if he doesn't act aggressive enough you pretty much instantly win, unlike in other games where even if one wasn't being aggressive the others would make up for it. The reverse of this is also true, since Springtrap is the only threat here he's more dangerous than the ones before in other games, so if he decides to be super aggressive then you're going to be having a bad time. Still though I don't think this game ever outright decides you lose like FNaF 2 does, so that's a plus. Most of the Phantoms barely ever show up, BB, Foxy, and Freddy are the only ones you'll consistently have to deal with which sucks since that's only half of them. Additionally one of the phantoms (Puppet) is so terrible that if you get caught by them your run is basically over. The way to get the true ending isn't intuitive at all and was designed 100% with internet guides in mind, I don't think that's very good design.
If you enjoyed any of the other FNaF games give this one a go, it's definitely one of the best FNaF has to offer and because of that is also a decent one to play if you just want to get into the series.