As I start with that though, don't think that I'm putting down any of the individual games. Every one is terrifying, intense, and horrific fun like we haven't had in a video game since the original Resident Evil.
Five Nights at Freddy's
The first game is our introduction to the world. The set-up and game-play is about as simple as it can get.
You play a night security guard for a Chuck-E-Cheese type establishment called Freddy Fazbear's Pizza. The place comes complete with security cameras and animatronics. You never actually move from the security office, you just watch the cameras as the robots mill about. You're given a power allowance for the shift though, so you have to keep an eye on its usage.
The thing is, the animatronics are somewhat faulty. As far as they know, there aren't supposed to be any people in the building after hours. So if they see you, they think you're a robot without a suit, so they take you and stuff you into one. Which results in a very wet, squishy death. Your only way to protect yourself is to keep an eye on where they are, and if they get too close, close the doors to your office. Just keep in mind keeping the doors closed uses power...
The game is very intense between checking the camera's, checking the doors, and listening for sounds which could let you know you're about to die. All this sets you up perfectly for the scenes where you fail and the animatronics lunge at the screen, prompting some genuine scares. As you might expect, the game proceeds over five nights, each night moving faster and increasingly intense.
Definitely an A+ start to the series.
Five Nights at Freddy's 2
As in the first game, you're limited to your office, using security camera's to keep an eye on who moves where. Power is less of an issue overall, but there is still a flashlight that can run out if you overuse it.
The second game also adds a lot onto the formula for the first game. There are more animatronics, and more ways for them to reach you. There is also a music box that must be kept wound, or it releases another entity which kills you no matter what you do.
Five Nights at Freddy's 2 also introduces mini-games occasionally after you die, which explains some of the backstory which, up until now has only been a collection of theories pieced together from things in the background of the first game.
The second game continues to be intense and frightening, even for those who grew immune to the first game's tactics. Rarely will you see a sequel as good as the original in any series. This one is.
Five Nights at Freddy's 3
While the third game holds onto the security guard in one spot formula, it continues to mix up everything else.
In addition to watching the building's rooms, you have a whole second layer to keep an eye on in the AC vents. The issues with power are completely gone, replaced with an unstable system of ventilation, sound ques, and camera feeds that need to be rebooted periodically.
While many of the old animatronics are back, they are just hallucinations, caused by the faulty AC in the building. There is really only one animatronic in this game which can kill you.
The third game also continues the mini-games, showing you things that happened between games and imparting even more of the story of the history of Freddy Fazbear's Pizza.
The series continues to be good and intense, keeping the formula close to the original, but mixing things up with new and innovative ways.
Five Nights at Freddy's 4
Now things have actually changed drastically. No longer are we a security guard at the pizzaria, but a young boy at home. Doors are also far enough apart now that you have to run back and forth between them, peeking out, and pulling them shut before some nightmare beast grabs you. The animatronics are now as terrifying as ever. (Minor spoiler: the nightmare animatronics are the young boy's imagination.)
The gameplay is different as well, focusing much more heavily on sound to determine where the monsters are and when you need to shut doors, as opposed to security cameras. This actually leaves you even more vulnerable to the jumpscares when they burst through the door.
The story of this game is actually the explanation of why one of the specific animatronics at Freddy Fazbear's Pizzaria is possessed. (Oh, yeah, that is the actual reason why the animatronics roam and kill night guards. All the animatronics are possessed by dead kids.)
Still, even with the differences, this game has that distinct Five Nights at Freddy's feel to it, and it continues to scare people every bit as well as the other three.
So there you have it, the Five Nights at Freddy's series. There's DLC scheduled for October, and then we'll see if any more games are added to the line-up. It's just a little sad that these games are only available on PC and not on any consoles (yet!). But if you can get the chance to play any of these fright-fests, definitely do so.
If you can't play it, I would definitely suggest you at least watch someone else do so. It's funny as hell watching them jump, and you can still try to piece the story together as they go. I would personally recommend Markiplier on Youtube.
So check it out!