Fredbear: left to rot

Fredbear's Family Diner is not seen in game while it was functioning, however it was presumably a traditional pizzeria and entertainment complex with one or more stages and a kitchen and dining area. The only animatronics that would have been used in Fredbear's Family Diner are Bonnie and the eponymous Fredbear.

At the time of the game the diner has fallen into disrepair after being abandoned due to the Bite of '83 which forced the company to rebrand as Freddy Fazbear's Pizza and eventually go into insolvency. The diner's underground area appears to have been used as a testing facility for Afton Robotics, which are accessed using the elevator found in Storage.

Story Fredbear's Family Diner and its past is expanded on in the Training Tapes. The diner operated as a restaurant and entertainment complex for children up until the time of the Bite of '83 in which Fredbear bit off the frontal lobe of a child in an accident. This resulted in both Fredbear and Bonnie being decommissioned and rebranded as a consequence. The fate of the pizzeria presumably follows the main story of the FNaF games up until the Missing Children's Incident in which five children were murdered by William Afton.

A detective/investigator [Phone Guy] is assisting the player to look for their missing son, who was kidnapped for Afton's experiments. ["...It doesn't make sense for the detective not to go in themselves—it's really weird..." - The creator doing a QnA about the game on the GJ page.] The player enters the now derelict Fredbear's Family Diner in order to look for evidence that will hopefully point towards the location of the prime suspect, William Afton. Afton has altered a lot of the underground testing facilities and has reprogrammed any remaining animatronics to act as a security system for the building. The player is tasked with deactivating the remaining security systems and collecting any evidence along the way while progressing deeper into the bowels of the diner to uncover the truth around their missing son.