How the toys of our youth lose their charm when thrust huge and noisy onto the screen. First, it was the Transformers, reduced to inelegant CGI monsters by Michael Bay’s effects crew. Next up? The real American heroes of G.I. Joe, whose back-stories are at least acknowledged by director Stephen Sommers (The Mummy, Van Helsing), but whose charisma is all but eclipsed by the movie’s raison d’être – namely, deafening explosions and expensive-looking set pieces.

Somewhat surprisingly, given Paramount’s reluctance to let critics anywhere near the movie prior to its release, Rise of the Cobra is a far cry from the unmitigated disaster of Bay’s latest sensory assault, Revenge of the Fallen. This is moviemaking geared toward children – namely, a generation of prepubescent boys weaned on tales of a military that’s always victorious. At its best, it’s mindless fun, and those expecting more will surely be disappointed.

The story, in brief: A Scottish arms dealer (Christopher Eccleston, of 28 Days Later) in league with the evil Cobra organization is on a Dr. Evil-inspired mission to capture a high-tech device capable of flattening cities  in a single strike. With it, he and fellow super-villains Storm Shadow (South Korea’s Byung-hun Lee) and the Baroness (Sienna Miller) plan to hold the world hostage.

Standing in their way are the Joes, a team of elite soldiers trained by grizzled veteran Gen. Hawk (Dennis Quaid, effectively authoritarian) in a top-secret facility beneath the Sahara Desert. Army pals Duke (Channing Tatum) and Ripcord (Marlon Wayans, whose attempts at comic relief fizzle consistently) become his latest recruits after surviving a Cobra ambush, and before long it’s their turn to protect Paris from annihilation.

Rise of the Cobra is an exercise in crudely edited chaos that unfolds like a video game, and with reason: A companion piece for Xbox, PlayStation and the Nintendo Wii, said to pick up where the movie leaves off, was released several days prior to opening weekend. (A line of action figures has already flooded the market.) But there are guilty pleasures to be had, especially as the Joes race through the City of Love in their nifty accelerator suits. They’re unable to save the Eiffel Tower, and the French, we are told, are “pretty upset.”

As is so often the case in movies like G.I. Joe, actions speak louder than words, and indeed, the dialogue here (courtesy of Stuart Beattie, David Elliot and Paul Lovett’s script) is entirely disposable, as is much of the plot. Sommers has assembled a fine cast – in particular, Eccleston and Quaid – to flesh out flimsy material. Whether he gets a chance to bring them back for a sequel depends entirely on how those preteen boys choose to spend their allowances.