What horror film is the subject here?

It took a mere 8 days to shoot this film.

To promote discord between actors, the directors deliberately gave them less food each day of shooting.

Some theatergoers experienced nausea from the handheld camera movements and actually had to leave to vomit. In some Toronto theatres, ushers asked patrons who where prone to motion sickness to sit in the aisle seat and to try not to "throw up on other people."

The actors were given no more than a 35-page outline of the mythology behind the plot before shooting began. All lines were improvised and nearly all the events in the film were unknown to the three actors beforehand, and were often on-camera surprises to them all.

When promoting the film, the producers claimed it was real footage. Some people still believe it.

This film was in the Guinness Book Of World Records for "Top Budget:Box Office Ratio" (for a mainstream feature film). The film cost $22,000 to make and made back $240.5 million, a ratio of $1 spent for every $10,931 made.

The working title was "The Black Hills Project."