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: You can see the threads moving the submarine underwater. (00:04:55)
Revealing mistake: You can see the wires on the handgun pointed at the two extraterrestrial children when the bad guys are staring in shock at the "floating gun."
Revealing mistake: There are two actual games played out: one in Huston and one in Tokyo - the score board has identical faulty light bulbs in both locations.
Revealing mistake: When the motorbike randomly explodes after Terri and Dave get out of the car, it is obvious that the explosion does not come from the bike, but from the shrub behind it, which also happened to creep up closer between shots. (00:07:30)
Revealing mistake: Walter and Joanne have two little girls at the beginning of the film, but then much later, there are suddenly two young boys seated at the table during breakfast. (01:17:00)