Corrected entry: The alien face hugger sacs were apparently suspended and filmed from below, then the film inverted to give the appearance that the sacs were rising up from the floor. When the crew discovers the sacs in the alien ship, a closeup shot reveals liquid running up the side of the sac and then "dripping" up into the air.
Corrected entry: Several scenes on the story boards and in the script did not make the final cut of the film. Some weren't even filmed at all. Some of these scenes included a sexual encounter between Dallas and Ripley, who have their moment spoiled in horror when Kane's corpse, which they ejected hours before, drifts in front of their view and bangs into the window. The other more controversial scene that was not even filmed, but only hinted at, was a 'rape' scene involving Lambert and the Alien. The Alien sliding its tail between Lambert's legs was originally intended to be the start of a bizarre sodomy/rape sequence, but director Ridley Scott thought better of it and decided not to film that scene. The only inclination of the alien sodomizing or raping Lambert left in the film is the fact that her corpse, which we only get a brief glimpse of hanging from the ceiling, is stark naked.
Corrected entry: When talking to 'Mother' the characters never seem to type enough keystrokes to account for the wording of their questions on the computer screen.
Corrected entry: In the rapid closeup sequence in which the alien kills Parker (Yaphet Kotto) by biting him right in the face, a freeze-frame viewing indicates that, at the point of impact, a honeydew melon was used to absorb the bite. Now a honeydew melon has a white external rind, and Kotto is a black actor. Why couldn't the SFX guys, at least, have painted the melon to match Kotto's complexion? This production error is, well, in your face. (01:33:35)
Corrected entry: When Ripley goes down to check out how Brett and Parker are doing with the repairs, she says: "Don't worry Parker. (pause) You'll get whatever's coming to you." In the short pause between these two sentences, you can hear Ripley say something like "You have". It seems to be a wrong line which has been deleted, but not properly. (00:22:05)
Corrected entry: 1. As captain, why send yourself, the only other pilot (Cain) and the weakest and most timid member of the crew (Lambert) to investigate an unknown and possibly dangerous planet? The better selection would have been Cain, Ripley (whose duties as warrant officer seem to be unclear) and one of the engineers, Bret or Parker. 2. Are we really to believe that the chain smoking and slightly built Lambert could help Dallas carry Cain's limp, space suit laden body thousands of meters, across rugged terrain back to the Nostromo? 3. The Nostromo can navigate itself to Earth through deep space - a navigator is not needed. 4. The Nostromo is just a 'tug' so why does it need a science officer and a lab filled with science equipment? 5. All the elaborate buttons and switches on the bridge and med lab have no labels or designators - how does the crew know what they're turning on or off? 6. Dallas makes two flippant decisions. First, to take off from the planet with needed repairs still underway. And second, to remove the face-hugger from Cain's face even thought it might kill him.
Corrected entry: The scene where the facehugger's acid blood eats through the medical bay's floor was done with actual sulphuric acid stained yellow.
Corrected entry: In the scene were the Alien attacks the man with the flamethrower in the vents, You can slightly see the clothes of the person who plays the Alien. (01:15:30)
Corrected entry: On DVD version: In the part where the chestburster has bursted and is looking up at the crew you see a drop of blood fall onto it's head. This is after all the blood has finished being sprayed everywhere.
Corrected entry: The 'chestburster' alien that rips open Kane's chest and escapes is about the size of a 500ml beer can, plus the tail and legs, right? Regardless of how inactive it was, there is absolutely nowhere in the human body that such a creature could hide. It is larger than a human heart. It could not hide in Kane's stomach or esophagus without causing a huge, incredibly painful blockage, and there are no other 'spaces' anywhere where it could go. Where was it hiding, then? It could not hide in the abdominal cavity because its phenomenal rate of growth means it must be eating something - and the only thing available is Kane himself. I think he'd notice. (00:56:20)
Corrected entry: On the special edition: go to the main menu, highlight special features, press right, and you will get the dossiers for the crew.
Corrected entry: In the scene where Bret is confronted by the alien in the landing gear bay, we see the alien 'unfolding' from a vent using backward folding bird-like legs. In every other scene the alien has forward bending, human-like legs. (01:07:30)
Corrected entry: When Ripley is setting the ship's self-destruct mechanism she goes to a panel in the floor. In this panel there are four holes with four screws next to them. When she inserts the first screw she has to manually lift up the cylinder to activate it. It also makes a sound as it is lifted. After she inserts the screw into the second cylinder it cuts to a view in front of her. The cylinder makes the same sound as it raises, but Ripley is not lifting this one. Her arms are doing nothing. When she activates the last cylinder she once again has to lift it up manually by the inserted screw. Based on the design of the mechanism it is apparent that all four cylinders have to be manually lifted, but Ripley does not lift the second cylinder. It lifts itself. (01:35:30)
Corrected entry: Just before landing, Dallas orders the Navigation lights turned on and we see rows of lights lighting up on Nostromo's belly. After landing, Dallas orders the flood lights turned on and we switch again to Nostromo's unlit belly (that should already be lit up with the nav lights) and we see the same rows of lights turned on again.
Corrected entry: When Brett is about to be killed by the alien, a close up shot of just his hat is shown when the alien's teeth impale his skull and his brains come pouring out. In slo-mo you can see that an alien hand is holding his head in place as it strikes. A split second later we see Brett's face, but there is no hand anywhere near him nor is the alien reaching out towards him. (01:07:50)