Five Nights at Freddy's theory SPOILER ALERT

So here's how I think it goes, involving the new game and the old game.

In the newly released game, you have no doors, but have a Freddy suit to hide in this suit is supposed to keep you safe when an animatronics enters the room, but it does not work on foxxy, or the marionette. Instead of 5characters there are 11 confirmed, but 13 have been observed. The 11 confirmed characters include: Freddy, Bonnie, Chica, Foxxy, Balloon boy (bb in the custom night), the marionette, the mangle, toy Freddy, toy bonnie, toy chica, and golden Freddy. the other 3 animatronics include: the Endo skeleton(thought to have been the frame that golden Freddy belonged to when his suit was stolen.), Balloon girl(like balloon boy but seems to not be a threat will be seen hiding under your desk), mysterious yellow creature (like some sort of demented smiley face with red cheeks this character is unpredictable and very rare, some think it might be a punishment for hiding in your suit too long or too often on night one.)

As the nights go on the caller wild inform you of certain things. On his first call he talks about hiding in your suit, you can hide in when ever AMD how ever long you want, he even states '' you will be golden'' golden huh? A reverence to him using the golden Freddy suit in the murder of the children. He then starts to talk about events happening that are involving the animatronics. Starts saying that the facial recognition is going haywire and the suits are being tampered with. He also mentions the one o the characters suits had been stolen. On the last night, you are informed that the place is being shut down and the last party will be held the next morning. You are also informed that you must stop working the night shift and guard duty for the day and make sure any one is safe from the animatronics. 

The guy that calls you is the killer. In the mini game death screen, it tells you the actual story. Game one, "give them cake'' shows you as Freddy giving cake to the children. In the upper of the screen there is a 7th child crying at the door, this child some what resembles the marionette in the game that you have to keep asleep. In give them cake, a purple car with a strange purple man come by and kill the child. My theory is that, this unknown child, is the marionette. Game two, "Foxxy'' you run out of your stage in pirates cove playing as foxxy to surprise five children. On your third run, the purple figure returns and is standing back stage. When you run out to the children, all five children are dead. I'm guessing this was the killer changing out of his stollen costume he used to kill the kids with. This also might explain how in the game hiding in the Freddy suit does not save you from foxxy, because he saw the human get out of the suit after killing the children. Game three: "give them gifts, give them life" in this game you play as the marionette. Youfly around, giving presents to 4 dead bodys, when done doing so, you return to the center of the screen and a second objective is given. "give them life'' nw you fly to each of the bodies. When you o, a pixel face of each Freddy character appears Bonnie(bottom left), chica(top left), Foxxy(bottom right), and Freddy (top right). This must be in relation to the marionette bent the original haunting spirit that made th other animatronics alive. The last two games confuse me as to how they belong. I bot games you play as Freddy chasing the marionette around the pizzeria. Dead bodies and blood scatter the building. In the final room you walk into, there is a body and an open present box. If you touch any bodies the game immediately ends and you are greeted with a jumpscare death by the marionette.

Now lets talk about killer ad how the bite of 87 was planned.

The new games is a prequel t the old game, so things kinda work backwards here.

The killer starts messing with the facial recognition of the characters, I hops of erasing any trace evidence of hi being the killer. At a guess, the now corrupted robots start to target any one (including you) wearing a security guard outfit. No knowing that this wont work, o the final night, being told you need to work the day shift final birthday party the killer decides it would be easier to get rid of yo as a security guard. You are also a threat to him because you have access to all the cameras. I the old game the bite of 87 is mentioned. You ar the victim of the bite. You live but are a vegetable. Unable to be evidence of the kill. Your paycheck eve says it was delivered for 1987. 

In the old game o night 4 the killer gets claimed finaly by the animatronics. Even though they have exacted their revenge, these spirits inside of the electronically faulty animatronics are still active and avengefull. They only remember that in their entire time, the killer was a guard. There will be no end until the machines are destroyed.

That's all I have for my theory. There is some hole here and there but I hope to improve this with more knowledge and discovery of the game's content over time.

EDIT
Shadow Freddy confirmed.
Shadow freddy, a new variation of Freddy and golden Freddy. Pitch black with white eyes and white teeth. Is seen sitting on the floor in the golden freddy pose in place of old bonnie