Like its predecessor, “Red 2” must have been a lot more fun for its cast to make than it is for us to watch it. The sequel to the geriatric spy flick, which was based on the comic mini-series by Warren Ellis and Cully Hamner, is more elaborate than its predecessor, but only proves that bigger is not necessarily better.

The screenplay by Jon and Erich Hoeber, who penned the adaptation of the original picture, continues the story pretty much without a break. Retired CIA agent Frank Moses (Bruce Willis) has settled down with Sarah (Mary-Louise Parker), the government check-writer he took up with in the initial installment. Frank’s a homebody now, but Sarah yearns for more adventure, so when Frank’s goofy old partner Marvin Boggs (John Malkovich) shows up to announce he and Frank are being targeted again, she’s more excited than Frank is. And when Marvin is apparently assassinated—leading to a mildly amusing funeral sequence—Frank is convinced the paranoid Boggs was right, especially after a cold-eyed government operative (Neal McDonough) shows up with a passel of SWAT types to take him down.

It would be unfair to give away too much of the convoluted plot about Cold War shenanigans that threaten to literally explode in the present, courtesy of an old nuclear device codenamed Nightshade. Suffice it to say that Boggs shows up again, remarkably fit; that he, Frank and Sarah are soon on the run but simultaneously on the track of their pursuers; and that legendary MI6 agent Victoria (Helen Mirren), called upon by her agency to terminate them, is soon a member of their team again. Others who become involve as the plot thickens are sultry Russian spy Katya (Catherine Zeta Jones), old Soviet spymaster Ivan (Brian Cox), Chinese contract killer Han (Byung-hun Lee), an international terrorist known as The Frog (David Thewlis) and eccentric British scientist Edward Bailey (Anthony Hopkins), long kept imprisoned by MI6.

“Red 2” soon becomes one of those films that go awry in the central elements—the forced banter between Willis and Parker and the big action sequences—but provide some chuckles in what amount to the throwaway moments. Thanks to the busy but silly script, Dean Parisot’s limp direction and Don Zimmerman’s tepid editing, there are entirely too many prolonged fight sequences, both with fists and guns, and car chases, and elaborate sequences involving assaults on the Kremlin and an Iranian embassy seem to go on forever. The material focused on Willis, Parker and Zeta-Jones, McDonough and Lee, Jones and Thewlis, and—surprisingly—Hopkins, whose character was probably conceived as a replacement for Morgan Freeman’s terminal retiree of the first installment but who proves very badly used, is all stale. But the bits involving the unruffled, sharp-tongued Mirren mostly work (especially when she shares space with Cox). And so does virtually every moment when Malkovich is onscreen. He’s really the movie’s saving grace; whenever he’s around to toss off some wacky remark or do one of his patented reaction shots, you almost forget the dross that’s going on around him. (That shouldn’t, however, be taken to mean that he should be promoted to starring status in a spin-off. His is the sort of character who shines on the sidelines, but would wilt under the spotlight.)

“Reds 2” has been given an elaborate production, with European locations providing some elegance even if Enrique Chediak’s cinematography lacks panache and the special effects fail to amaze (indeed, some of them look pretty chintzy). But Alan Silvestri’s score sounds sadly generic, like a good deal of the dialogue it accompanies (especially when somebody is holding a gun on somebody else and drones on about his intentions).

It would be nice to be more enthusiastic about an action comedy that puts older actors in the limelight. But while the comedy of “Reds 2” occasionally works—especially when Malkovich is around—the action elements are mostly a drag.