Goofs

The nurse's car is a Pontiac, but the car going over the cliff after she is thrown out is a Dodge.

Thor's jumpsuit has bloodstains on the chest and right arm before his surgery. When he stumbles into the outer office the bloodstains are gone, and when he confronts the nurse they're visible again.

Derek takes a dead police officer's gun, a Model 1911 Colt, and is next seen with a German Luger.

During the "ending" car chase, Joe Rogers' (the reporter) hat is different while he is driving the car as opposed to when he is outside the car before the chase and after the chase. The hat before and after the chase has a brim which is UP in the back and DOWN in the front. However, when the scene cuts to the interior of him driving the car, his hat's brim is UP both in the front and the back.

When Thor shoots Billy as he is escaping in the car, the laser does no damage to the car, despite the heat generated by the gun, as evidenced earlier when he shot Alice in the pool (the pool water was boiling).

When Dr. Brandt removes the two bullets from Thor's shoulder, the bullets are not only "pristine" and not the least deformed, they're also still in their shell casings.

When the guy who picks up the alien explains how to operate his car, he describes how a three-speed manual shift works; yet when they subsequently pull up to the gas station, the chrome trim piece on the trunk clearly reads "Powerglide," Chevrolet's name for its automatic transmission.

When Thor shoots Billy in the car, the car automatically stops despite the fact that Billy was stepping on the gas to get away. The car should have kept going until it hit something.

The teenagers speak English so the viewers can understand them, but arriving from outer space with suitcase-like instruments is another thing. When they first exit their ship and set up their instruments to take readings, one of the suitcases even labeled inside as a "Multi-Channel Mixer."

During the chase through town, the men shooting at the car with the alien are clearly faking it. The hammers of the automatic pistols (Browning Highpower 9mms) are down in the lowered position, and the slides do not cycle in recoil to load a new shell. The "muzzle flash" is simply a scratch drawn on the film post-production.

About half of the film is supposed to take place at night; they say things like "when it gets light" and the interiors of the car are dark. Despite this, it is clearly daylight in every single exterior shot.

The alien teenagers' ray-gun supposedly strips the flesh from living beings, rendering them as skeletons. However, the skeleton used is obviously a suspended medical dummy as it has a fastening plate attached to the top of its skull.

Early in the movie the aliens believe earth has no intelligent life, but later when the hero brings the girl to the site where her dog was killed by one of the aliens, they park on a paved area with a guard rail which is only a few yards from the dog's skeleton. This parking area would easily have been visible to the aliens and been evidence of intelligent life.

When Derek and Betty discover Professor Simpson's skeleton, the wires used to tie the rib cage together are obvious.

In the opening scene at the observatory, in one shot an insect is flying around in the frame. Since it is closer to the light source, it seems to glow. Since this was an ultra-low budget production, there was no alternative take that could be used.