Goofs

Dr. Karol Noyman is killed by an explosion in his lab. When his alien controlled corpse shows up, the corpse is intact and doesn't even have any wounds or burns.

To occupy Noyman's body the alien moves the flowers and presumably must dig it out, but when Penner and others visit the grave it is undisturbed.

When leaving bunker for last time Maj. Jay kills 3 aliens, but when they drive away there are only 2 corpses are on ground.

After leaving bunker to find alien ship Maj. Jay is attaked by 5 aliens and kills 4. The fifth disappears.

The plane crashes into side of mountain, but both the pilot's corpse and approaching footprints are on level ground.

If the cab of the truck is radiation proof, the hand-held geiger counter Lamont uses would detect nothing.

When Major Jay takes the encased in plaster alien out of the pickup, he carries him with little effort. The alien in plaster would probable need two people to carry him.

The Hockey team is called the Rovers by the announcer, but the teams are the Montreal Canadiens and the Detroit Redwings.

When the alien invasion occurs, it's apparently daylight all around the world at the same time.

The B-17 bomber crashes into a target laid out in sandbags on the ground. It is stock footage of an Air Force test experiment related to remote-controlled flying bombs. In practice, the plane would have been pilotless and would have been loaded with high explosives.

The same shot of the same dead men walking over a hillside near the bunker is used over and over.

The surveillance monitor in the bunker cuts from one thing to another as if the footage were carefully edited in real time.

The aircraft that crashes into a hill clearly hits a large white painted target suggesting that it was film of some military exercise.

When Penner and others are at Noyman's grave, wire is visible through dirt when alien footprints approach.

The B-17 pilot who was killed to deliver the alien's message crashes his plane into a mountain outside of Syracuse, New York. There are no mountains near or around Syracuse.

It's repeatedly stated that the invaders' major advantage against the Earth is the fact that they're invisible. Yet by inhabiting the bodies of dead Earthmen, they give up this advantage, to no obvious purpose.

At 5:17 Phyllis Penner offers to drive Dr. John Lamont to the airport, at 13:16 Dr. Lamont drives back to the airport by himself, in theory stealing Ms. Penners car.

All aliens use Noyman's voice even when his corpse is not around.

Though the invaders' spaceship in the scenes toward the film's end is supposed to be invisible, it's actually visible throughout the sequence until just before it's destroyed, when it briefly does become invisible.

Why would aliens block transmissions only after the sound wave experiments?

In the opening sequences, the narrator refers to Dr. Karol Noymann as "Carl" Noymann, a mistake repeated in the credits.

The moon is referred to as a planet.

Alien says one final warning will be given but one is given at hockey match and a second at the football game.