It's barely spring, but summer arrives with a boom in 2013's first worthwhile blockbuster, G. I. Joe: Retaliation. Picking up threads left dangling from the first film no one liked, this sequel finds the elite military unit ambushed by terrorists Cobra and out for revenge. Dwayne “The Rock” Johnson once again elevates whatever role he's in as Joe leader Roadblock, while everyone from Adrienne Palicki to Jonathan Pryce and Ray Stevenson have a blast wholly committing to their wacky roles. Though toy-line inspired, director Jon M. Chu makes action flick gumbo. Heavy explosions? You'll find them. Mountain-side ninja battles? They're in there. Plus toyetic vehicles, a lunatic plan for world domination and a boxing match where both fighters are holding and using handguns while they punch. Big, shiny and loud, G.I. Joe: Retaliation won't win any awards, but it's a fine waste of two hours.