There are 4 in the main series and then there is the spin-off series Prometheus.
This is a sequel to Prometheus, which is set 10 years after as a colony ship, Covenant, travels to a dark world previously thought to be a paradise, where they encounter the sole inhabitant, the synthetic David from the first film.
They are planning on making a fifth Alien movie with Ripley and everyone but it was put on hold as Ridley Scott makes the Prometheus series.
The Witch is definitely a slow-burner but it was so good. Truthfully, though, I had to watch it twice...watching it in the theater first, I fell asleep a bit just because it was hard to understand. Picked it up at Redbox (once it was released on DVD) and thought it was dope.
I found this article about dead projects some of them sound cool and interesting
Quote:
In Air Disturbance the horrific action takes place at 35,000 feet on a transcontinental flight from Los Angeles to Toronto. Dylan Walsh plays Sam Davidson, a widowed father of two, whose wife recently committed suicide. When strange atmospheric conditions begin to affect the aircraft, Sam protects his children and his psychic girlfriend from some of the other passengers, particularly a fanatical minister (Robert Englund) who believes that the supernatural phenomena could be a sign from God
Quote:
At the Mountains of Madness
Based on a tale by H.P. Lovecraft, the film would detail a gruesome discovery made during the 1930's by a scientific expedition to the South Pole, which hints at the true origin of mankind having come from elder gods from another planet. They soon realize that during this discovery they may have also accidentally awakened prehistoric creatures...
Filming was originally rumored to begin sometime in June of 2011.
Tom Cruise is apparently interested in starring in the film.
Guillermo del Toro intends to make the movie "really uncomfortable and nasty."
Guillermo del Toro revealed in an interview that the film would not be gory and the victims in the film would be "absorbed" in an "eerie and scary" way by the creatures.
