As far as fairy tales and movie adaptations go, Jack and the Beanstalk is one that hasn't been as used up and worn out as some of the bigger ones over the last few years (*ahem* Snow White). That is probably the reason Hollywood decided to give the Jack and the Beanstalk story a brand-spanking-new movie makeover in Jack the Giant Slayer. As usual, this fairytale was done no favors in the process.
Despite the charismatic charm of Nicholas Hoult (Warm Bodies) in the titular role of Jack, and despite some pretty above-average CGI effects, Jack the Giant Slayer failed to capture the magic of the original fairytale, or even offer up a compelling action/adventure family film.
There are many reasons for this, most of which lay in the fact that (as good as it was) CGI was over-used. When a film like this relies too heavily on computer generated effects, even if they are top grade, it eventually and continually removes the viewer from the universe the filmmakers have tried to create. And, as you may already know, when an audience is reminded that the movie is just a movie then the movie has already failed.
Besides being catapulted out of Jack's cinematic world due to over-reliance on CGI, the story itself was beefed out in a decent way to fill the runtime of a feature film. On the flip side, the story and the dialogue was obviously geared toward a younger audience, and so for the most part silly and juvenile.
The characters came across as caricatures, and the giants themselves seemed trite and formulaic. I think, in re-creating a fairytale like this for the big screen, a fresh approach is always needed. The filmmakers seemed to be trying to make the giants an amalgamation of all the obscene and oafish characters in the literary and cinematic world. The result was a set of giants that didn't seem believable or particularly compelling.
Bryan Singer (X2) directed this film with mediocre interest. It wasn't terrible, and there were a few intriguing scenes at the beginning during a story-telling/narration sequence. But after that it was pretty much all downhill with formulaic camera angles and scene shots, barely better than a made-for-TV movie by the end.
So my advice is, if you have kids under the age of 10 hankering for a family adventure movie, take them to Jack the Giant Killer. You won't suffer too much during the movie, and they'll be able to appreciate the film because their artistic pallette hasn't matured yet.