The film depicts a comedic and satirical alien invasion of Earth by Martians, who arrive with seemingly friendly intentions but quickly reveal their hostile nature.
The story revolves around multiple characters, including President James Dale (played by Jack Nicholson), his press secretary Jerry Ross (played by Martin Short), First Lady Marsha Dale (played by Glenn Close), and a range of other civilians, soldiers, and government officials.
The Martians, depicted as short, green, and bug-eyed creatures, arrive on Earth in flying saucers and initially appear friendly, offering gestures of peace and goodwill. However, their true intentions are soon revealed when they begin attacking humans with deadly ray guns, reducing famous landmarks and cities to rubble.
As chaos ensues and humanity fights back against the alien invaders, various subplots unfold, including a romance between a sleazy gambler named Art Land (played by Jack Black) and a waitress named Barbara Land (played by Annette Bening), and a resistance movement led by former casino employee Richie Norris (played by Lukas Haas).
In the climax of the film, President Dale attempts to negotiate with the Martians but is ultimately captured and subjected to a grotesque and humiliating interrogation. However, the tables are turned when it is revealed that the Martians have a fatal weakness: the sound of Slim Whitman’s yodeling song “Indian Love Call,” which causes their heads to explode.
In a last-ditch effort to save humanity, the surviving humans broadcast the song across the globe, causing the Martians to retreat in agony. The Earth is saved, and humanity celebrates its victory over the alien invaders.
“Mars Attacks!” is praised for its campy humor, over-the-top visual effects, and eclectic ensemble cast. It pays homage to 1950s B-movies and science fiction pulp novels while delivering a satirical take on themes of warfare, politics, and human nature.