SpongeBob SquarePants displays maturity -- up to a point

To be honest, I wasn't always enamored of "SpongeBob SquarePants." Too often it was merely stupid instead of being deliberately, artistically stoopid, dimwitted with a purpose. Although it soon established itself as the most popular cartoon in Nickelodeon history on its debut in 1999, and has been the top-rated show among preteen kids for six years, I personally preferred "Rugrats" or "Ren & Stimpy," the shows that started Nick's animation renaissance, if not "Doug."

Yet the new special "Atlantis SquarePantis" offers an opportunity to reassess "SpongeBob," and even a curmudgeonly TV critic has to admit it finds the show in a glorious maturity -- in its craft if not necessarily in its subject matter. (What would "SpongeBob" be without Patrick Starfish acting like a 5-year-old on a birthday-cake sugar rush from time to time?)

Although "Atlantis SquarePantis" is being promoted as "SpongeBob's" first made-for-TV movie, it's really just an extended episode, clocking in at 45 minutes when it debuts at 7 p.m. Monday on Nick, padded out by the inevitable 15-minute making-of documentary "Behind the Pantis," proclaimed "the most special special that's ever been called a special."

The story is fairly simple. SpongeBob and Patrick stumble on the missing half of a medallion from the lost city of Atlantis. When they unite the halves, the whole Bikini Bottom gang is carried off in a magic underwater bus to the actual city of Atlantis, where they're greeted by the Lord Royal Highness, given voice by David Bowie in one of the show's periodic celebrity guest spots. Atlantis being a utopian community where war has been banned and all is ideal, of course the more-than-mortal Bikini Bottom visitors do their best to muddy things up, in any number of ways.

Yet the simplicity is this show's grace. "Atlantis SquarePantis" operates like a fine sitcom at the peak of its powers, in that the characters are so well-defined at this point they almost seem to write their own jokes. The optimistic, well-intentioned SpongeBob, the idiotic Patrick, the greedy Mr. Krabs, the megalomaniacal Plankton, the inquisitive Sandy the squirrel and most of all the cranky but caring Squidward simply go off together and interact, and that's all the program needs to create a lively yarn.

"Atlantis SquarePantis" wasn't written by show creator Stephen Hillenburg, or by Paul Tibbitt, who scripted some of the most popular episodes as well as "The SpongeBob SquarePants Movie" three years ago, but instead by the team of Casey Alexander, Zeus Cervas, Steven Banks and Dani Michaeli. Working off the considerable foundation that's already been built, they come up with crafty little ways of showcasing each character.

The magic bus, it turns out, is powered by song, so each character gets to fuel it with part of a medley -- until it comes around to Patrick and he almost causes the thing to crash. That's a lovely device that plays to the show's strengths, in the way its audience has come to love its sing-songy interludes. (What parent didn't have to endure endless renditions of the tune "Best Day Ever" when that episode debuted?)

Two subplots dominate. Atlantis has banned war and locked up all its weapons, but Plankton wants to seize control of them and take over the world. Meanwhile, SpongeBob and Patrick go off to see the "oldest living bubble," which of course couldn't be in more jeopardy if you asked a dog to catch it in its teeth.

Yet Squidward, yes Squidward, almost steals the show by falling in love with Atlantis and its arts. He has really undergone a lovely transition and development over the years, so that what was once just a crabby, misanthropic squid is now a fully realized character, tentative and cautious, perhaps, but eager to appreciate the wonder and beauty of the world -- and so often thwarted by the others in that noble desire.

That's "Atlantis SquarePantis," and "SpongeBob SquarePants," at their best, finding new nuances in the characters and new ways of expressing them in animation. "SpongeBob" is at the peak of its powers right now, and the only thing it has to be concerned about in its sea realm is, yes, what all shows must fear: jumping the shark.

Remotely interesting: The Discovery Channel is bringing back its "Planet Earth" series for those who missed it the first time. The 11-part miniseries will run two segments a week starting at 7 p.m. Sunday. … Terri Irwin keeps her husband's memory alive -- for herself and TV viewers -- with "In Steve's Footsteps," at 9 p.m. Sunday on Animal Planet. … With nerds taking over television this fall, they land a beachhead on the Independent Film Channel with the debut of the documentary "Darkon," about people re-enacting medieval-style battles outside Baltimore, at 8 p.m. Monday.

WLS Channel 7's State Street studio has won a special-recognition award from the Chicago chapter of the American Institute of Architects for Vojo Narancic's design.

End of the dial: CBS Radio has installed a new female-oriented adult-contemporary music format at WCKG 105.9-FM. Dave Robbins is the new vice president and general manager with Mike Peterson as program director, the same roles they hold at CBS sibling station country WUSN 99.5-FM.

John Symons has taken the evening shift as disc jockey at WLIT 93.9-FM from 7 to midnight.

Waste Watcher's choice

Now here's a "based-on-fact" movie a Waste Watcher can love. "Elvis Meets Nixon" reimagines the true occasion when a bored, pills-addled Elvis Presley flew off to the White House to present himself to President Nixon as an agent in the war on drugs. Allan Arkush, who handled camp so ably in "Rock and Roll High School," directs with a humorous flair while keeping things real, with Rick Peters as Elvis and Bob Gunton as Nixon. It's at 8 p.m. today on WCPX Channel 38.