Continuity mistake: When Land is presenting to the investors during the invasion, a saucer flies behind him just as he puts on his hat. In the next shot, that saucer is gone, though there are others still in the background. It didn't move quickly enough to get offscreen in that time. (01:11:45)
Continuity mistake: When the Martians are attacking the people in Nevada, the truck which Natalie is on falls to the ground, but when Jason runs to save her it's back on its wheels. (00:41:25)
Continuity mistake: The first time we see Tom Jones' backup dancers, they are about three feet apart. In the next shot, they are directly next to each other. (01:12:40)
Revealing mistake: When the Nancy Reagan chandelier fall on the first lady, it is obviously a dummy with a wig. (01:10:30)
Continuity mistake: When Byron, Barbara and the others are going to escape from the casino, the Martians break a wall behind them. The hole is different in the following shots. (01:14:40)
Factual error: When the President holds the meeting in the room where all the countries are on the back wall in blue, Australia is not only the wrong shape (too long) but the wrong way around (the rounded part should be on the other side)
Continuity mistake: When we first meet Lands in the casino, Art sticks a cigarette in his mouth. But in the next shot when he hands Barbara some chips the cigarette disappears.
Continuity mistake: Right before the president is killed, the Martians shoot around in the room and knock over Australia, leaving the lighted outline visible. When Mitch the bodyguard is killed, the cutout is back, intact. When the president starts his speech ("Why are you doing this?"), we see the lighted outline and the cutout is missing yet again. (01:27:15)
Continuity mistake: At the beginning when the President is deciding to go public to the American people, Jerry moves his arms into his lap twice. (00:05:25)
Continuity mistake: When Byron's ex-wife is driving the bus, she sees her two sons playing at the arcade, when the bus passes right in front of the building. She makes an announcement to the passengers, then she brakes, but the bus stops right in front of the arcade. (00:15:25)
Chosen answer: While the movie is a parody of the 50's sci-fi B-movies, the film is actually based on the Topps 1962 science fiction trading card collection called "Mars Attacks!", which tells the tale of the Martians' attack.
Bishop73