You have reached Noob vs. 1000 Freddys. There are FNAF villains on each of the five maps, which represent five different worlds.
You won't have to fight all of them at once, because the game is split into five maps, each with multiple levels. In each level, you have to kill a certain number of animatronics, like Freddy, Foxxy, and others, before they kill you, which happens when they use up all of your 100 health points and you lose.
Use WASD to move around, the mouse to aim and shoot, R to reload, Shift to run faster, and Spacebar to jump. Use the F key to pick up things, and the CTRL key to duck.
As you finish levels and make money, you can go to the Weapons Shop and buy better ones to use against your enemies.
Have fun and good luck!