YMMV / Indiana Jones and the Kingdom of the Crystal Skull
Broken Base: Reviewers, fans, casual viewers, all possible groups are split!
Contested Sequel: It's hard to pin down a specific ratio, but opinions are sharply divided over whether it's a worthy follow-up to the original trilogy or not.
Critical Dissonance: Critics generally enjoyed it, while fans seem to loathe it. On Rotten Tomatoes, the audience score is lower than the critics score.
Fanfic Fuel: This installment definitively establishes that Indy was an active OSS agent for the entirety of World War II proper note The main trilogy takes place in the years just prior to the war, and that he spent around a decade spying against the Soviets with the CIA during the Cold War. That's around seventeen years of undocumented high-stakes adventures.
Fanon Discontinuity: Since this is to Indiana Jones as the prequels were to Star Wars in terms of divisiveness, there's a lot of Indy fans who like to pretend this film doesn't exist.
Inferred Holocaust: The tribe that lived near the temple most likely were killed by the departing spacescraft or drowned by the river flooding the valley, had any members survived the massacre from the Russians.
For all the flak the reveal of the crystal skull belonging to a race of interdimensonal beings got. Most probably don't realize that it was actually used first in an early Indy story, the comic adaptation of Indiana Jones and the Fate of Atlantis which revealed that most of the technology the Altatians had were given to them by aliens.
Mis-blamed: Lucas gets blamed for the decision to make Soviets the villains rather than Nazis like in the previous films. In reality, due to the harrowing experience of making Schindler's List, Spielberg felt he could no longer make movies featuring Nazis as simply stock villains, although Harrison Ford's advanced age since the previous film also accounted for it.
Lucas only wrote the story draft (along with Jeff Nathanson), the one who wrote the screenplay was David Koepp. But you would be excused for not knowing that based on how no one ever brings that up in reviews for the film and such.
Lucas was deadset on having Indy survive a nuclear explosion by using a fridge as shelter, but he never said that the nuclear explosion had to be that close or that Indy should fly away in the fridge (one of the first scripts, Indiana Jones and the Saucermen from Mars, has Indy ducking in a foxhole and turning the fridge over his head as a cover). That belongs to Koepp and Spielberg.
Although Lucas had already eliminated the "Old Indy" bookends from the DVD version of The Young Indiana Jones Chronicles, which showed 93 years-old Indy being cared by a daughter, it was Spielberg who vetoed Indy having a daughter in this film, feeling that it would be a retreat of Kelly and Ian Malcolm from The Lost World: Jurassic Park.
Narm: At the end Indy says the secret Mayan treasure was knowledge. "Knowledge was their treasure." He says this with a big stupid grin on his face while the cast looks directly at the camera.
The original script for Back to the Future from 1982 featured Marty McFly surviving a nuclear blast in a fridge-time machine, in order to return to the present. This was scrapped because it was too expensive to pull off, and there were concerns that kids who watched the movie might climb into abandoned refrigerators to "play Marty." If that sounds at all familiar, it's because Spielberg was also executive producer of that film, and also used the idea in an earlier version of the script in the earlier years of the franchise that was later adapted into this movie.
One True Pairing: There is one aspect of this movie about which pretty much everyone can agree, and that is that Karen Allen's return as Marion Ravenwood is FUCKING AWESOME.
The Scrappy: Mutt, to some people. It doesn't help that he's played by Shia Labeouf, who isn't a particularly well-liked actor.
In fact, practically every brand new character introduced in Crystal Skull is hated for little reason beyond being in Crystal Skull.
Special Effect Failure: The prairie dogs, the monkeys and the aliens have been derided for this. The chase scene in the final act utilizes a good deal of conspicuous green screen as well.
They Changed It, Now It Sucks: A common complaint of its disappointed viewers. Some long term fans feel the shift away from supernatural/fantasy elements towards sci-fi and aliens was a move too far.
Indy's struggles with old age actually could have made for some genuinely compelling drama, and they could have been the basis for evolving the character into a Badass Grandpa who has to rely on his smarts. In the final product, though, Indy seems so unrealistically invincible that the movie feels more like an excuse for Ford and co. to play out their "older guy hero" fantasies.
Some fans were actually perfectly fine with the idea of moving Indy into a Cold War setting, and argue that the Soviets, the aliens, and the Badass Biker sidekick gave the movie all the makings of an awesome 1950's throwback. The problem? Instead of bringing in the practical effects to make the Genre Throwback feel authentic, they loaded it up with Conspicuous CGI that made it look like just another generic 2000's sci-fi blockbuster. It didn't exactly help that they cast Shia LaBeouf right after he'd become known for his role in Michael Bay's Transformers.
What The Hell, Casting Agency?: Shia Labeouf's casting as Mutt wasn't well-received, as he hadn't exactly made a great name for himself among audiences in regards to his abilities or capability to be an Action Hero. The fact Mutt turned out to be Indy's son didn't help matters either.