So, I am a fan of the FNAF games, but when I heard a 3rd one was coming out, I had the same reaction as everyone else. "Another? Hasn't Scott milked the franchise enough?" Then I saw the trailer and started reading up on it, and the pictures on the Steam Greenlight page made it look nothing like the other ones.
Five Nights at Freddy's 2 I felt was just a rehash of the first with more animatronics. The third however, contained only 1 animatronic, and like the second one, 0 doors. Also in this one, you have to keep track of the ventilation so you don't hallucinate, the cameras may go out, or you wont be able to distract the monster. You also have to keep track of 10 rooms AND 5 vents. If it doesn't sound difficult to you, then you will have to try it for yourself.
I beat all 5 nights, leading to "Nightmare Mode," the 6th night. Now THAT is hard. Most of the game seems completely random and hard to manage. I have made it anywhere from 2 am - 5 am (That time I was pissed). As of me writing this, I have put a total of 3 hours into this game. I recommend playing this one, whether you have played the previous ones or not.