As a professional film critic -- whatever that may be -- I have a handful of concrete rules by which I ply my ostensible trade, and not reviewing films by or heavily involving close friends is one of them. Which presents a bit of a problem when tasked with writing about any given Muppet movie.

No, I can't claim I've ever knocked back a beer with Kermit the Frog, gone shopping with Miss Piggy or got close to any of the cloth-skinned crowd without the dividing wall of a television screen between us, but damn it if I don't feel closer to them than I do to any number of human names in my address book. Growing up, I knew their vaudeville numbers inside out. I'd record the umpteenth rerun of even the Crystal Gayle episode with completist's excitement. And I treasured my Kermit toothbrush until the bristles began falling out, ignoring the fact that he wasn't the most dentally appropriate role model.

Still, love isn't blindness: I've forgivingly acknowledged when The Muppets have collectively misstepped, as they (and their flesh-and-blood controllers) did rather too often in their later years. "Muppets From Space" and "Muppet Treasure Island," in particular, were tawdry misapplications of their scatty showbiz appeal, which is why 2011's back-to-basics "The Muppets" was such a gratifying return. Their act works best when it sticks, in name and nature, to their variety-show roots, and the delightful "Muppets Most Wanted" wisely follows suit.

That's perhaps the only respect in which James Bobin's chipper, deliberately shabby film might be called "wise." Exuberant silliness is the order of the day, with Bobin and co-writer Nicholas Stoller firing cheap sight gags, gloriously terrible puns and random, daffy star cameos at the crowd like so many chickens launched squawking from a cannon. Some land, some don't -- I was cackling too consistently to keep score -- but until an oddly sluggish final reel, the onslaught is deliciously relentless, like being beaten over the head with a marshmallow pillow, and taking a bite with each blow.

"The Muppets" was such a blessedly zappy relief that it was easy to overlook its tonal and structural shortcomings: an influsion of 21st-century irony that didn't seem entirely coordinated with the gang's own sense of self-satire, and a quest narrative driven by colorless new recruit Walter (okay, he's sort of tangerine, but insipid all the same) that didn't leave enough room for familiar favorites to cut loose. The first scene of "Muppets Most Wanted" picks up, rather ingeniously, right where the last film's closing number left off, and that same ironic distance initially seems to have hung around: an introductory song about the inferiority of sequels (written with customarily cockeyed fizz by Bret McKenzie, the best human friend the franchise could hope for) is certainly clever, but threatens a film more about Muppet mythos than The Muppets themselves.

Happily, it's little more than a threat, as Bobin and Stoller sally forth with a daft yarn that combines the series' steadfast storytelling modes of chaotic backstage drama and, well, a great Muppet caper. Now reunited, The Muppets immediately sign up with plainly sleazy talent manager Dominic Badguy (Ricky Gervais) and embark on an ill-rehearsed European tour -- little realizing that their act is a mere front for a series of bank heists engineered by dastardly Kermit lookalike Konstantin. Mistaken identity games naturally ensue, with Kermit hauled off to a Russian gulag ruled with a travel-iron fist by Tina Fey's Broadway-loving wardress. Konstantin, meanwhile, gives the bemused Muppets free rein over their show, with amusingly calamitous results. (If there's anything keeping "Muppets Most Wanted" from an A- grade, it's that we only get a few tantalizing seconds of Miss Piggy's flamingo-assisted "Macarena" rendition.)

This is far closer to the bittier, plottier rhythm of The Muppets' first three film ventures, and that's a pretty welcome throwback -- only in the final reel, an over-extended wedding climax at the Tower of London that's surprisingly short on planted gags, does the contraption begin to creak. (At 106 minutes, the film may be a smidge too much of a good thing.) You'll either go with the flow or you won't, and much the same goes for the film's loopy brand of anti-humor: be it a Berlin taxi headed for "Plotpointberg" or an onstage cameo from Christoph Waltz dancing the, er, waltz, the very best Muppet jokes are the ones that least bear scrutiny.

Bobin obviously isn't taking the proceedings seriously -- aside from the indefatigably earnest Kermit, who is? But he's also a man who knows that absurdity requires absolute commitment: a casually invested journeyman couldn't pull off the more ambitiously inspired lunacy of Fey's riotous, Mel Brooks-worthy "In the Gulag" production number, which may well the franchise's finest moment to feature no Muppets at all. Still, the greatest rewards of this warmly scattershot outing are those that find the comfy motley crew sparking and sparring off each other, indulging in their own ageless shtick and resisting too many new tricks. (Hey, even Walter blends in this time round.) Everything old is old again in "Muppets Most Wanted," and while admitting to a certain friendly bias, I wouldn't want it any other way.