Sometimes I think I just don't know anything about kids' films anymore. Having grown up in one of the golden ages of "children's cinema" (The Neverending Story, Labyrinth, The Black Stallion, and so on), I often find myself lamenting the dearth of strong storytelling or darkness in films made for children these days.

But then I remember that there were just as many witlessly enjoyable, instantly forgettable films released then, too, and I feel a little less bleak about the whole situation.

So, with that muddle of an introduction behind us, how about a trip to Journey 2: The Mysterious Island, guys?!

It's should be no surprise to find that Journey 2 falls into the second category (i.e. witlessly enjoyable), thanks mostly to the megawatt presence of Dwayne "The Rock" Johnson, who has such a riot of a time sending himself up that when he's on screen, you'll think this is the most fun you've had in ages.

Fortunately, he's on screen for the bulk of the film. The rest of the film that surrounds him, however, is the flimsiest of narratives, and our heroes never face any real sense of peril.

Sean Anderson (Josh Hutcherson), the intrepid teenage explorer from 2008's Journey To The Centre Of The Earth, is busted breaking into a satellite station to attempt to decode a scrambled signal. His new stepfather, Hank (Johnson), a bang-up ex-Navy dude who just wants to bond with Sean, helps him break the code: one and two syllable names from the work of Jules Verne = morse code!

It turns out, as Sean suspected, that the message is from his grandfather Alexander (Michael Caine), who claims to have found Verne's Mysterious Island, and within seconds Sean is packing his bag for Palau, the nearest actual location to the Island's alleged coordinates. Following a conveniently perfunctory conversation with Sean's mom (Kristin Davis) about setting their son straight, Hank's off for the ride as well.

In Palau, the pair employ the services of local tour-guide Gabato (Luiz Guzman, on Generic Latino Stereotype auto-pilot) and his pretty daughter Kailani (Vanessa Hudgens), chartering a helicopter to the Mysterious Island itself, where granddad, miniature elephants, giant bees, G-rated romance, and other "Vernian" highlights await.

Following in its predecessor's footsteps, Journey 2 uses 3D in a pleasingly old-fashioned manner; indeed, it takes those old school tropes - things flying out of the screen - and applies them to knowingly ridiculous scenarios such as berries being pinged off Johnson's popping pecs (of course). There are some nice flying sequences, and a rather beautiful use of 3D atmospherics when flakes of gold fall from a volcano.

Unlike most 3D films, it's quite lovely to look at, too: the landscapes have the glorious/ridiculous lushness of matte paintings and, of all things, Hudson River school artist Frederick Edwin Church's tropical vistas. In another nice throwback-y touch, many of the 'mysterious' plants are obviously plastic and outlandish, a little like the cellophane flowers that sprang from the beds of Munchkinland.

However, the characters and the story are competent at best. Johnson's natural charm and firm grasp of his own personal brand of self-satire lifts his material, and Hutcherson gives a limited role a winning energy, but the rest of the cast are left with little more than stock reactions and exposition.

In particular, Caine's Alexander is unrelentingly mean to Hank, which seems an odd choice seeing as Hank is fun, kind, supportive of his stepson's enthusiasm for adventure and knows how to make a two-hit scuba outfit from a Ziploc bag and a snorkel, whereas Alexander is an unreliable fanatic who abandoned his family to pursue his own selfish eccentricities.

Perhaps director Brad Peyton was going for some sort of ill-advised "nerds' revenge" theme, where the sporty and successful guy paradoxically comes under fire from the academic, but it gives an otherwise harmless entertainment an unpleasant edge of meanness.

Hank being Hank, however, doesn't let it get him down: he just pulls out a ukulele and sings the grumpy old man a cover of What A Wonderful World. It certainly is with you in it, Dwayne.

- two stars