Silent Hills (lost build of cancelled sequel to "Silent Hill" horror game series; 2015)
Silent Hills was to be a horror video game, a new installment in the Silent Hill series (despite its simple title).
The game was announced in 2012, and was going to use the Fox Engine. On August 12, 2014, a teaser titled "P.T" was released, under a fake developer name: "7780s Studio". The teaser was later revealed, after playing, to be a teaser for a new Silent Hill game. The demo featured the player wandering around a house with no immediate reference to Silent Hill, later seeing the protagonist wake up in Silent Hill.
In 2015, director Hideo Kojima was scheduled to be laid off by the end of the year, which left the fate of the game uncertain. Until, in April 2015, the game's co-director annonuced that the project was cancelled. 
Footage of the demo can be easily found on the Internet, as many popular YouTubers covered the demo before the project was scrapped.
- Silent Hills Cancelled, Konami Confirms - GameSpot