Adaptation Displacement: The trading card series from the 60s and the comic series from the 90s are known well among pop-culture geekdom but most people recognize these aliens from this movie.
Accidental Innuendo: Martian "paper" looks suspiciously like condom wrappers.
The Martian who killed Danny DeVito's character, he was just standing there while Danny's character tries to make a deal with him. Was he contemplating his proposal before he decided "ah screw it, I wanna zap him", or he didn't understand a word he said and was like "yeah, whatever"?
The Martians may be redneck trailer trash like Ritchie's parents, and a Flying Saucer is just like a pick-up truck to them.
Grandma might not be such a "space case" - she might just have a uniquely mordant sense of humor. She might also be messing with her family a little. She knows that, except for Richie, they all have a low opinion of her mental acuity already, so she might as well have some fun with it.
Given the sheer level of Too Dumb to Live he displays with the "woman", right up until she's bitten his finger off, it's hard to wonder if Jerry isn't already drunk or high by that point.
The Martian Leader's angry reaction by the Martian Girl's death. Is he genuinely touched by the death of his best spy who was probably a good friend of his (or maybe even more) and thus he wants to avenge her or is he simply furious because the assassination attempt failed?
Was the translation machine built by the scientists actually effective at translating their messages, making the Martians lying liars or was it just consistently mistranslating their warnings of impending doominess as messages of peace or did the Martians have some sort of bizarro language in which they always said the opposite of what they really meant?
Also the scene where the translation machine was used to translate the Martian leader's broadcast. The translation made no sense, so it seems more likely the machine just didn't work. Then again, maybe they were just intentionally saying nonsense just to screw with the humans, having gathered on they forgave too easily? Or again, perhaps the machine simply had not quite locked onto the language yet.
The "international sign of the donut" was likely a sincere gesture in which the parties agree to war, though it does not seem to matter to the Martians whether the humans understand that or not.
Do the Martians' heads rupture from a specific frequency and pitch of the sound waves from Slim Whitman's vibrato or is it more that the music is so terrible to them, it actually triggers a physiological reaction?
Angst? What Angst?: Taffy doesn't seem bothered at all by the fact that her parents and entire community she grew up with were all just brutally killed as she's giving medals to Richie and his grandmother. Especially when you are now the new President of the United States.
"Indian Love Call" by Slim Whitman. The tune that destroys all of the remaining Martians.
Broken Base: Detractors of the film feel that taking such an All-Star Cast and giving many of them small roles is a huge They Wasted a Perfectly Good Character, while for the fans seeing so many big name Hollywood actors being treated like expendable B-movie Red Shirts is part of the irreverent, subversive fun.
Crosses the Line Twice: The Martian Girl disintegrating the First Dog with a ray gun? Horrific and sad. The First Lady immediately throwing the dog's skull at the Martian in a panic? Funny.
Cult Classic: It was a Box Office Bomb and got at best mixed reviews back in the day. It's developed quite a strong fanbase in later years, however.
Germans Love David Hasselhoff: Released a few months after Independence Day, the biggest hit of its year, Mars Attacks! flopped in theaters in the US. It did much better business in Europe and has since become a regular favorite on satellite movie channels.
Harsher in Hindsight: There's a shot of the World Trade Center 15 minutes into the movie. In a blink-and-you-miss-it shot later on, we see the Twin Towers tumbling over like giant dominoes.
The ending features Natalie Portman's character awarding medals to Richie and his grandmother after they save the world in an apparent homage to the ending of the originalStar Wars. Portman would go on to appear in the Star Warsprequels as Princess Leia's mother. Even better: The Phantom Menace ends with an award ceremony that homages that very same scene, with Portman's character once again presiding over it.
If you've played Team Fortress 2, Tom Jones' cameo will probably result in a giggle, as mentioning him is somewhat of a Running Gag in the supplemental comics and videos. Though where Tom Jones shows up to be a badass in this film, in the comic Unhappy Returns he instead spends one panel alive before being abruptly killed off.
This wouldn't be the last time that Jack Black and Danny DeVito would work together, their dead essences ended up in Jumanji.
The Martian Ambassador was brought into the Capitol claiming to apologize for his people's misdeeds. What does he do? Reduce everyone to skeletons.
The Martian Emperor when he turns down his chance for redemption and impales the President in the chest with a flag.
The Martian race as a whole crosses this by attacking a planet completely unprovoked with the intent of wiping out all life For the Evulz.
Narm Charm: The film's CGI effects have not aged well and appear rather dated nowadays, but seeing how the film is a loving homage to numerous sci-fi flicks of the '50s, the dated CGI can be seen as an unintentional Spiritual Successor to the numerous instances of Special Effect Failure seen in those old movies such as obvious model buildings, visible strings holding up rockets and planes, and cars that are clearly toys.
Retroactive Recognition: Jack Black, Ray J and Sarah Jessica Parker (to a lesser extent) were not famous when this movie came out and would only later be recognized, making this all-star cast even more impressive. Natalie Portman was decently known but not nearly as big as she would become in the years since.
There's a part of the fanbase that genuinely wanted the Martians to win. Justified since the humans in the film can be every bit as goofy as the Martians themselves (especially General Decker, who's basically a Martian in human skin), making for a decent Black Comedy.
The Congress massacre scene, in particular, tends to bring out this response in people. Whenever someone posts a clip of it on YouTube there are invariably comments along the lines of "Why are the Martians the villains again?"
Slow-Paced Beginning: It takes some time for the Martians to show up, instead focusing on the human characters such as the President himself. However, considering how laughable the characters are, you probably won't mind watching them for a while.
Some of the CGI effects are a bit dated, but the look and feel of the movie make them Narm Charm for the most part... except for the CGI dove moments before the Martian Ambassador kills it. That bird looks like something straight out of the early Pixar Shorts.
In the scene where one of the aliens is disguised as a human girl, she's constantly chewing on gum (as explained later, she needs it to breathe). Later, Martin Short's character flirts with her and puts his finger in her mouth, which she bites off. As he removes his hand, he rips off part of her fake skin, exposing the alien jaw. She is then seen still chewing on the gum. However, the exposed alien teeth remain closed the whole time, while they should be shown chewing.
Squick: Seeing Nathalie and her dog's bodies with their heads swapped is not only disturbing/terrifying, but can also make you feel queasy. Same goes for seeing Donald's still living head hooked up to life support systems while his disembodied heart can still be heard beating.
The brief establishing shot of New York City was taken from 1970s b-roll footage as One World Trade Center is missing its antenna and some of the other buildings in the complex are absent. Along with that, the World Financial Center is completely absent from the scene.
The destruction montage also contains very blatant stock footage from Hindis at a mass gathering, a shot from Ghostbusters II and two shots from Rapa-Nui (1994).
Too Bleak, Stopped Caring: On one side, the Martians are psychos slaughtering everything For the Evulz. On the other, most of the human characters are unlikable people. It certainly aimed for an inversion, as the latter meeting horrible deaths at the hands of the former is supposed to be part of the fun. But it depends on the viewer liking the strong Black Comedy. It helps however, that the tables start turning as soon as the cast is whittled down to just its few sympathetic characters.
Ugly Cute: The small frame, large eyes, and little "ack ack" noises are kind of adorable when you look past their skeletons-with-massive-brains look, particularly the Martian Leader when he smiles and he sheds a tear for the president.
Why did this film not get an Oscar nomination? The Martians seriously look amazing! Look at the texture in their brains. The flying saucers also look great. The best shots are the opening title sequence where the saucers leave Mars and fly towards Earth and that bird's eye view of the saucer landing in the Nevada desert. Of course, even if the film was nominated, it would still be going up against eventual winner Independence Day.
The Practical Effects and the miniature work look quite good, pretty on par with those from Independence Day (especially Big Ben getting blown up), and the destruction of the Galaxy Hotel was a real Las Vegas hotel with its (already scheduled in advance) demolition filmed by the movie crew.
The original cards
Moment of Awesome: The Earthlings getting payback on the Martians after all the crap they put them through... and later when their planet explodes.
Values Dissonance: "Saucers Invade China" describes the Chinese people as a primitive, superstitious nation who don't even know what an airplane is and who pose no resistance towards the Martian invaders, believing the assault to be a form of divine retribution. The artwork features yellow-skinned, slant-eyed, conical hat-wearing peasants being destroyed by flying saucers. A few decades later, such artwork would no longer be acceptable.