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The best quality of 2009's G.I. Joe: The Rise of Cobra was one that nearly everyone derided: childishness. Stephen Sommers' action movie duplicated the world of eight-year-old boys playing with action figures. The characters had ludicrous names, swapped nonsensical dialogue that sounded like kids playing at being adults, and had gravity-defying fights with ninjas and explosions inside one secret base after another. It was playtime writ very large.
The sequel, however, has a problem. It's made for 12-year-old boys and comes complete with righteous quoting of Jay-Z and a farcical attempt to invoke geopolitical realism. Retaliation is very much concerned with appearing cool, whereas the original knew very well that one secret weapon can always be trumped by another and that girls were icky things in tight leather who would try to kill you, either with a machine-gun or girl germs.
As with 2011's Fast Five, G.I. Joe: Retaliation uses Dwayne Johnson to juice up a sequel, and while his formidable physique suits the warfare-on-steroids milieu, the actor may be too serious for this material. That's almost certainly a first for an ex-wrestler formerly known as The Rock. Johnson's Roadblock takes over as the focus of the US Army's special forces G.I. Joe unit from Channing Tatum's Duke, and in fact once their enemies in Cobra (your basic rule-the-world cabal) finish tarring the outfit, there are only three members left, and the path to global domination is clear.
To go into the plot any further is wasteful, particularly in a movie whose idea of wit is the line, ''I don't know why they call it a waterboard; I wasn't bored at all.'' Unfortunately, the trio of Joes' method of resistance involves finding their retired founder, and since Clint Eastwood obviously had more sense, Bruce Willis took the gig. Willis deploys his deadpan nonchalance and joins in the bloodless mass homicide, but he merely adds to the predominance of gruff tough-guy talk.
Even more arbitrary are the moments of studious self-reflection, which try to humanise and make genuine characters that should be anything but. Director Jon M. Chu has mainly made dance movies - two Step Up flicks and Justin Bieber: Never Say Never - but the action scenes aren't particularly well choreographed or photographed. What's most galling is that G.I. Joe: Retaliation simply lacks adolescent imagination. Far too many grown-ups have worked on these by-the-numbers battles.