Trivia: The darkness that emerges and begins to kill the guests was actually created when the animators took film of dancing naked women and mirrored the image over and over.
Trivia: The 2009 horror film "Dark House" was a much-lower-budget, B-grade remake of 1999's "House on Haunted Hill," with virtually identical plot, characters and motivations (i.e., a flamboyant amusement park mogul offers people money to stay in a technologically-rigged spook house that turns out to really be haunted). Interestingly, legendary horror actor Jeffrey Combs appeared in both films. In "House on Haunted Hill," Combs played the murderous ghost of a mad doctor who really haunts the house; in "Dark House," Combs played the flamboyant amusement park mogul.
Trivia: The first film by production company Dark Castle Entertainment. Dark Castle was originally founded to exclusively make big-budget remakes of films by famed B-movie producer/director William Castle. (The company even borrows the word "Castle" from his name.) This is why Dark Castle's first two films were "House on Haunted Hill (1999) " and "Thirteen Ghosts (2001) " - they were remakes of two of Castle's most well-known works. However, after these two films were released, the executives at Dark Castle decided to diversify their output, and began to work on films not inspired by William Castle's work.