Factual error: Casey arrives at the desert landing in a jeep that is flagged with 4 stars (for a 4 star general) although he is only a 3 star general (as evident by the 3 stars on his shoulder boards). (00:33:30 - 00:35:25)
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)
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