Sean Gilman’s review published on Letterboxd :
Not as terrible as I initially thought five years ago, but mostly because it's just not the Indiana Jones movie I want. Spielberg updates his character from the swashbuckling adventure films of the 1930s to the plastic silliness of the 1950s, situating him in a wholly artificial world, where the mannequins, Russians and CGI monkeys all convey the same amount of expressive depth.
In this it's an inversion of the first film, which took the premise of a ridiculous kids' serial and treated it like it was for adults. In RAIDERS, Jones is a grown up: he drinks a lot, fights angry, is greedy for treasure (indeed, he is effectively mirrored by the film's villain, when Belloq says they are "two sides of the same coin" you actually believe it) and his monkey friend turns out to be a Nazi. In CRYSTAL SKULL, a gang of friendly monkeys teach young Mud to swing through the jungle Tarzan-style so he can execute a convenient last-minute rescue.
Thematically the two films are ultimately similar: both require Jones to resist the temptation to learn the final bit of knowledge (he mustn't look at the contents of the Ark, or learn what the aliens know lest his brain melt). But again, the difference in approach: in RAIDERS, his internal conflict is palpable (at one point he threatens to blow the Ark up to save Marion, but Belloq knows it is a hollow threat). But the CRYSTAL SKULL drives John Hurt insane, and Jones never shows the slightest interest in it or its secrets: he just wants to rescue his friends and family and stop the Russians from winning.
None of this is particularly objectionable, in theory there's nothing wrong with a 50s-set live-action cartoon. And Spielberg, as always, executes his actions scenes perfectly. As the film is composed almost entirely of action scenes, there's a lot to admire about the movie (including some of Spielberg's most haunting images). But the dialogue just makes my skin crawl. It's weirdly repetitive and tautological ("Their treasure wasn't gold, it was knowledge. Knowledge was their treasure.") and for some reason Jones constantly refers to Hurt's character by name in the way that people occasionally do in movies but rarely in real-life, such that "Ox" becomes part of every line ("Ox, do this. Ox, come here. Where's Ox? Ox ox ox.") Normally I wouldn't care about such things, but it's just so annoying. The earlier Indiana Jones films aren't exactly subtle or minimalist, but they were rarely so obvious or over-written.
But perhaps the dialogue is intentionally terrible?