There aren't many reasons to see Gulliver's Travels. In trying to fill several different identities, it fails at all of them.
This movie wants to be a family film and an adaptation of Jonathan Swift's story and a Jack Black comedy vehicle0, but each identity robs from the others. Black's outlandish style is cramped, messages for kids are tainted by inappropriate material, and Swift's cultural themes are reduced to a dance sequence—seriously!
In this rendering, Lemuel Gulliver is a typical Jack Black character: a dopey-but-lovable loser who plays too much Guitar Hero and works in a New York newspaper's mailroom. Thanks to low self-confidence, he's stuck in his dead-end job and won't ask out his crush, Darcy, a travel editor (Amanda Peet), who seems to like him (but why she does is a mystery). Characters repeatedly mention that Gulliver, as a mailroom employee, is one of the "little people" and life won't get any bigger than this for him (get the metaphor?).
When Gulliver lies to Darcy about being a travel writer, she spends two whole minutes glancing at some unpublished writings he stole off the internet and hires him on the spot for a "small" article about Bermuda that requires a 3-week solo boat trip leaving right away. Good first gig, huh? Of course, Gulliver ends up not in Bermuda but on the island of Lilliput, where he finds himself a giant among tiny men. For the first time, he is the big (very big) man on campus. He strikes up a friendship with Horatio (Jason Segal), a man of low station who is convinced he'll never amount to anything—especially not winning the heart of the princess (Emily Blunt). While Gulliver helps Horatio court the princess, a rival suitor looks for revenge—and to rid Lilliput of Gulliver forever.
There are some genuinely funny bits, like a recurring gag about a far-too-complicated warning bell system. And the reveal of a coffee maker built by the Lilliputians for Gulliver is inspired. But the film takes the gag of building Gulliver-sized items too far when these 6-inch people build their giant guest a mansion and … a robot? The problem with most of the humor is that the gags feel forced, only for the sake of laughter. One scene retained from the book is when Gulliver saves a burning palace by urinating on it. In the movie, there is no value to the act other than the gross-out gag of urine hitting people in the face. I got the impression that the writers had no idea what they were trying to say with their humor. As C. S. Lewis wrote, "Humor involves a sense of proportion and a power of seeing yourself from the outside." There is none of either here.
Jonathan Swift used his wit not to primarily make his readers laugh but as a weapon for social change. But the original work's satirical bent is simply confused for comedy here. Wen you know the political meanings behind Swift's book, it's antithetical—if not ludicrous—to think of this satire becoming broad family comedy. And so, this adaptation feels like a high school literature student's project that tries to explain a dense piece of writing by only hitting plot points—and completely missing the underlying themes.