Let's get it out of the way right at the top: This felt-and-fur follow-up isn't as inspired as 2011's giddy Muppets relaunch. Sorry to sound like a grumpy Statler or cranky Waldorf, but there it is. First off, there's no Jason Segel, whose sincere love for Jim Henson's gang was infectious. Second, and more to the point, there isn't the same sense of discovery. Last time around, generations both old and new embraced Kermit & Co. like long-lost friends. But now, well, it's hard to miss something that's only been gone for the blink of an eye. Still, one thing that both films do have is a playful, knowing sense of self. And Muppets Most Wanted starts off strong with the winkingly self-referential song-and-dance number, ''We're Doing a Sequel,'' where the filmmakers beat the audience to the punch, acknowledging with toe-tapping good humor that ''everybody knows that the sequel's never quite as good.'' After that, though, the film loses some of its fizz by giving in to a so-so caper plot that unintentionally proves the axiom they were just satirizing.
Flush with the success of their last outing, the Muppets are approached by an oily showbiz promoter named Dominic Badguy (the ever-game Ricky Gervais) who cons them into embarking on a world tour against Kermit's misgivings. Meanwhile, Dominic's partner in crime, a villainous Kermit lookalike named Constantine (''the world's most dangerous frog'') busts out of a Siberian gulag in Shawshank fashion. It's only a matter of time before Constantine pretends to be Kermit to orchestrate a string of heists across Europe that lead to the theft of England's crown jewels while Kermit is shipped off to the gulag to sit in a freezing cell and wonder why his pals aren't coming to save him. The truth is, they don't know he's missing, even though the new ''Kermit'' is acting awfully strange and speaking in a vaguely Slavic accent. The gag and it's a priceless one is that the only difference between Constantine and Kermit is a mole on Constantine's face. Cover it up, and everyone buys that he's Kermit. So what if he sounds like Yakov Smirnoff?
Besides Gervais, the movie features Modern Family's Ty Burrell as an Inspector Clouseau-like Interpol agent and Tina Fey as a gulag guard who has a thick-as-Borscht, Boris-and-Natasha accent and an unrequited crush on Kermie. As the Muppets crisscross Europe, name-checking German cities like ''Vomitdorf'' and ''Poopenbergen,'' the film fires off buckshot one-liners and celebrity cameos from the likes of Salma Hayek, Usher, Celine Dion, and that kiddie favorite, Christoph Waltz. As usual, the songs (written by Flight of the Conchords' Bret McKenzie) are so catchy you'll be humming them for days. But even though it's always a joy to spend a couple of hours in the company of Fozzie, Miss Piggy, and Animal, you can't help but get the feeling that this time around something is missing. B