Revealing mistake: Many times throughout the movie, people are shot and they bleed, but their clothes don't have holes from where the bullets hit them. The most noticeable examples are when the teacher is shot at the end, and when the big gun fight between the girls breaks out in the lighthouse.
Revealing mistake: When the two dinosaurs are fighting besides the cliff, Malone and Jennifer Holmes hide behind a rock overlooking the cliff. One of the dinosaurs sweeps its tail, and knocks the two lovebirds over the cliff, but they fall onto a rock jutting out from the cliff. After we see them fall, there is a wide shot of the dinosaur swinging its tail. He swings it one way, then the other. After he swings it the first way, the tail freezes in mid-air for a split second, then swings the other way. It's obviously the same shot of the first tail swing, but played in reverse with a pause in between.
Revealing mistake: When Biro stabs the Imperial soldier with his sword, it's obvious that the sword is angled to miss his body. (01:30:50)
Revealing mistake: At the scene where all the spy kids are fighting the waiters, watch Gary as he is fighting. The waiter he is fighting throws him back, but then Gary activates his rockets shoes. Yet to activate those shoes you have to tap them together. The rocket shoes activate a few seconds before Gary tapped his heels together.
Revealing mistake: During the scene where the two teenage stars are outrunning the tidal wave through the hills, the girl is supposedly carrying her baby sibling strapped to her chest. However, the legs that can be seen dangling out of the baby-carrier belong to a dummy.
Revealing mistake: As Reg fights with one of the baddies with the chainsaws, as the baddie take a swing with the chainsaw he misses and cuts into the wooden door. You can clearly see that a vertical cut has already been made in the wood though, to help the chainsaw get in and cut. (01:17:55)
Revealing mistake: When the Interceptor team flies in their cargo plane to Mexico to investigate the UFO crash, several shots filmed from the front show the six of them all in the cockpit (not in the body of the plane.) They're seated as they might be in a car, three across, front and back. The window of the cockpit looks remarkably similar to a station wagon windshield, down to the large rectangular front windshield, and even the rear view mirror is in place.
Revealing mistake: After the bounty hunter, who changes three times throughout the movie, changes into the Reverend, he is in front of someone else who is a stand-in for the real Reverend but is obviously not.
Revealing mistake: As Machine Gun Joe runs slowly runs over a fisherman in a small brook, he stops and "peels out" on his head. You can see a film crewman in the driver's seat doing the actual carnage.
Revealing mistake: This film was shot in Page Arizona with is pretty far north in the "high country". When they first drive up to the meteor side, there is Saguaro cactus that are only a couple of feet high with huge arms and a neon greenish color. These only grow on the desert floor in Arizona and they certainly are not neon colored. Additionally, the arms don't start appearing until they are much taller as they grow them to balance themselves since they have a very shallow root system.