Although the game came out on December 2018, the earliest version of the game was released in 2016. That version is on Steam under the name "Hello Neighbor Demo"
The game was originally supposed to come out on August 29, 2018. However, due to criticism over the Beta, the game was delayed to December 8, 2018.
The achievement "I ain't afraid of no ghost" is a double reference. The name references Ghostbusters, while the picture for the achievement is a ghost from Pac-Man