Five Nights at Freddy's (FNAF) is a popular survival horror game that first appeared in 2014. In the game, the player takes on the role of a night security guard who must monitor a pizzeria from midnight to 6 AM. The animatronic animals that entertain during the day become aggressive at night and try to attack the guard.

The gameplay involves monitoring security cameras and closing doors to prevent the animatronics from entering the security office. The player must manage their limited power supply while keeping an eye on the animatronics' movements. If an animatronic reaches the security office or the power runs out, the game is over.

The game's eerie atmosphere, jump scares, and mystery surrounding the backstory have made it a hit among horror game fans. The player can unlock different endings and hidden secrets by completing various tasks and puzzles throughout the game.

FNAF has spawned a series of sequels, spin-offs, books, and merchandise, all set in the same fictional universe. The game has also been adapted into movies and a virtual reality experience. With its unique gameplay and captivating story, Five Nights at Freddy's has become a staple of the horror game genre.