Goofs

When Steve looks at the page torn from the encyclopedia in the endgame, the shot shows the page still attached to the book, even after the girl had torn it out.

When Steve and Sally are driving to dinner and he stops the car the radio is not on but when he restarts it the radio pops on with a news flash.

When Steve and Sally stop the car in the mountains Steve again gets sexually aggressive with Sally. The dog in the back seat barks again and stops Steve. Yet when they drive off a minute later the dog is not in the back seat at all. It is not likely they would be leaving the dog behind in the desert.

When Steve first proposes a trip to Mystery Mountain, Dan says it "hasn't seen a human being since 1900 when the prospectors gave it up." But when they arrive, Steve says a pile of rocks "wasn't there last winter." And when Sally later goes to the mountain, she says, "I've been out here with Steve before and I know that cave wasn't here."

When Steve explodes the first plane it is dark. When he arrives at Sally's house it is daylight outside. Then when driving to dinner it is dark again.

When the plane explodes, a piece of the model, still attached to the support wire, swings back into frame.

Wires visible when the plane explodes.

The black wires that are used to make the brain fly are clearly visible in several scenes.

When the Russian diplomat arrives for the meeting, he places his hat on the outer desk. As he enters the conference room, the hat falls to the floor.

When the Colonel is killed in the Conference Room, he falls to the floor. But then his body disappears. His body is nowhere to be seen.

Despite finding numerous bodies at the plane crash site, investigators find only one small piece of the aircraft.

When Steve and Dan stop their Jeep at the road block on Mystery Mountain, the sound is out of sync. Agar's mouth moves but no sound comes out.

When Steve falls to the floor of the cave, the stand to the boom mic and power cable are visible on the right.

At the crash site you can see the shadow of some crew member pass in front of Steve.

Even after being occupied by Gor, Steve thinks Sally is imagining things when she tells him about Vol.

Sally was not allowed to see the bodies at the plane crash but she tells her Dad that the bodies were burned "just like Dan"

After Steve defeats Gor, everything goes "back to normal." However, Steve is in a lot of trouble, especially in all the destruction he caused when at the meeting with the General. How can he possibly explain his behavior? No one is going to believe that he was under the mind control of a "brain from outer space."

When Steve and Dan are standing by the jeep at the end of the road, the boom's reflection is visible in the windshield. Also, when Steve and Sally are in the convertible, it is visible in the in the wing window.

After the explosion outside the Indian Springs conference room, the voice that comes over the load-speaker, announcing the warning, is Sally's father, John Fallon. Actor Thomas Browne Henry was the loud-speaker voice.