(CNN) -- Remember the Muppets? Silly question -- you're old enough to read, so they probably helped teach you.
Back when I was kid, they were huge. "The Muppet Show" ran five seasons, 1976-1981, and spawned half a dozen film spin-offs.
The first Muppet movie ("More entertaining than humanly possible!") boasted cameos by Bob Hope, Mel Brooks, Edgar Bergen, Milton Berle, Steve Martin and Richard Pryor -- not to mention Orson Welles -- a bill that positioned Kermit and company as the natural heirs to a half-century or more of prime-time vaudeville shtick.
But the brand has fallen into neglect, and it's entirely possible that an otherwise pop savvy 10-year-old wouldn't know his Scooter from his Waldorf. ("Fred the frog?" my son guessed, when I asked him to name one. "And isn't there a pig?")
Enter Jason Segel, who fessed up to a fetish for singing puppets in "Forgetting Sarah Marshall" and who has taken up the challenge of making Jim Henson's fabric-and-thread creations relevant to today's digital generation.
Segel, who stars and co-wrote (with "Sarah Marshall" director Nicholas Stoller), grabs the bull by the horns, so to speak, by acknowledging that the Muppets' glory days are long gone. That strategy risks making this comeback vehicle too much of a nostalgia trip to entice the kiddies, but their parents will probably lap it up.
Gary and Walter are brothers, and inseparable; except that Gary (Segel) is flesh and blood, and Walter ... well, let's just say there's a reason why Walter's favorite show is "The Muppets."
When Gary invites his girlfriend Mary (Amy Adams) for a romantic getaway to Los Angeles, it's only natural that he would invite Walter along too: For as long as they both can remember, it's been Walter's dream to visit the Muppet Studios.
But when they get there, the building is dilapidated and on the verge of falling into the hands of an unscrupulous oilman, Tex Richman (Chris Cooper). The only way to save it is to persuade Kermit to round up the old gang and put on a telethon: a comeback comedy special.
It's not exactly a fresh idea, but Segel and debut director James Bobin ("Flight of the Conchords") amuse themselves -- and us -- by poking fun at the cornball conventions of movie musicals: When Mary breaks into a melancholy ballad, the sudden downpour on her window pane doesn't come from the heavens, but a gardener's hose. A song-and-dance routine involving the entire population of "Smalltown" climaxes in the citizens collapsing into a heap, exhausted.
In fact, this early showstopper -- "Life's a Happy Song" -- is easily the pick of the new tunes, an infectiously jaunty number written by "Flight of the Conchords' " Bret McKenzie. Too many of the rest are strictly novelty items, including an intentionally awful barbershop rendition of "Smells Like Teen Spirit" and Chris Cooper rapping, badly.
"Man or Muppet," which is supposed to reflect the identity crisis of the two brothers, doesn't make much sense in the circumstances. We can see pretty clearly which is which and where the 2-foot hand puppet really belongs.
I hate to be a party pooper. At its best, this is a bright, colorful, perfectly innocuous amusement, but it's also pretty slapdash and disappointingly sluggish. Tim Burton and Paul Reubens worked this line of parodic faux innocence better in "Pee-wee's Big Adventure" 25 years ago (so did Amy Adams in "Enchanted").
Segel hasn't given himself enough to do as Gary, whose defining characteristic is neglecting Mary -- and if you're going to go to the trouble of inventing a new Muppet (Walter), why make him a bland nonentity?
As for the show's true stars, Kermit and Miss Piggy, it's nice to have them back, but I have to say they've never had the same spark since original voice artists Jim Henson and Frank Oz passed the baton to Steve Whitmire and Eric Jacobson. Piggy, in particular, is a pale shadow of the psychotic diva she used to be -- just don't tell that to Jack Black, the guest star she kidnaps and, uh, hogties when no other celebrity volunteers for the telethon.
A mixed bag then: "The Muppets" isn't the best or the worst of Kermit's big-screen capers. At least it's a reminder that here's one frog who isn't about to croak.