It has taken 18 years for the Simpsons to make it to the multiplex, and it doesn’t take 18 seconds to come up with likely reasons for the delay. The creators of The Simpsons Movie faced an obvious quandary: When you’ve spent years giving away great material week after week for the price of sitting through a few commercials, what more can you offer to induce people to endure the expense and hassle of a theatrical feature?

Film adaptations of TV action series can benefit from more expensive special effects and from the kind of widescreen immersion that can’t be achieved at home. Comedies can go raunchier. For cartoon material, more money can be lavished on smoother animation. But The Simpsons isn’t particularly action-oriented; it is too family-oriented to significantly up the ribaldry; and it would be catastrophic to monkey with the characters’ trademark visual simplicity.

In fact, director David Silverman and his team, including 11 — count ‘em, 11 — credited writers and four vaguely defined consultants, have done some of the above in minor ways. Mostly, however, they have constructed a longer, more complex story and exploited the compositional differences of a widescreen format. (For all but the first few minutes, the film is presented in an aspect ratio of 2.35:1, the widest ratio currently in common use.)

To answer the most important question: Yes, they do make it worthwhile.

But first, before we go into details, in the name of full disclosure: Back in the ’80s, my first film critic gig was at the late, still (by some of us) lamented L.A. Reader. I had already filled in for one of the editors for a few months, and one person’s copy was a sheer joy to edit: hilariously funny, printer-ready, not even a typo. That person was … Richard Meltzer.

Ba da boom.

Actually, there was someone else whose copy was hilariously funny and printer-ready, and with only the very occasional typo, and #that# person was Matt Groening, pre-Simpsons, but already drawing Life In Hell, in addition to writing a column that was originally about music but had long since expanded to include, well, whatever Matt wanted. Even before that, I had been a Groening fan, thanks to “Flummox,” a truly great parody of the Filmex calendar. (Criminy! Time flies, so I’d better explain: Filmex was L.A.’s first big film festival, in the Mesozoic days before AFI Fest and the Los Angeles Film Festival.)

Still, I’m not recusing myself from writing about a friend’s work, partly because in 1991 I found myself uncomfortably assigned to turn out a review of The Simpsons’ third-season opener for a trade paper. My reaction was less-than-glowing, and so was my review. When I ran into Matt a few days later, he was surprised at my take but there was no awkwardness; he had been a critic himself, so he knew the score. (Now I feel awkward about it, because, when I’ve rewatched that episode in recent years, it is way funnier than I remembered.)

But the main reason I’m not recusing myself is that I really howled at The Simpsons Movie. If I hadn’t, I would have handed off the assignment to someone else.

The central plot thread involves Homer (voice of Dan Castellaneta) being responsible for so befouling Springfield’s lake the town is forcibly quarantined by EPA Chief Russ Cargill (Albert Brooks, billed, as always on The Simpsons, as A. Brooks) and President Schwarzenegger (Harry Shearer). The family manages to escape a lynch mob and move to Alaska, but Homer’s selfishness is so disgusting that the rest of the family, even Bart (Nancy Cartwright), gives up on him. In the end, Homer has to rise above his natural instincts (and amazing brain deficiencies) to win back the love of his family and the respect — or, at least, the tolerance — of his neighbors.

Much in the manner of South Park: Bigger Longer & Uncut, the film very quickly confronts the “Why would anyone pay to see The Simpsons?” issue, one of several jokes playing off the viewers’ assumed knowledge of the franchise, of Fox and of television in general.

The animation style is almost entirely consistent with the show (which has itself sometimes experimented, as when Homer passed into a 3-D world in “Treehouse of Horror VI”). The shots of the torch-bearing mob are fancier, but not enough to distract; and some Disney stylings are used for the always honorable purpose of making fun of Disney stylings. But the most obvious difference here is the way some visual gags are staged to accommodate and take advantage of the wider screen ratio. At a press conference supporting the release, Silverman and others talked about watching It’s a Mad Mad Mad Mad World (ugh!) and, less predictably, Bad Day at Black Rock as models for widescreen composition.

There is one teeny sexual joke — arguably the film’s most brilliant visual gag — early on, involving a naked Bart, that would presumably have been a bit much for broadcast TV. I think there is also sexual innuendo when Homer, after losing a team of sled dogs, moans, “Why does everything I whip leave me?” I’m not quite sure what the innuendo is, I just know it sounds dirty.

Asked at the press conference, when asked about the urge to do material in the movie that might go too far for TV, Simpsons godfather James L. Brooks (Broadcast News, Spanglish) said in the early days they could get away with much more, but recently things have grown more oppressive.

A more oppressive culture might have something to do with the PG-13 rating for a feature that has (I think) one “damn,” one or two mild sexual moments and far less gruesome violence than most “Treehouse of Horror” segments. The official MPAA explanation is “Irreverent Humor Throughout” — which (naturally) couldn’t have pleased the filmmakers more.

There is worthwhile stuff during the closing credits. Weirdly, the credits themselves include cast listings for seemingly every regular character in The Simpsons universe, many of whom either were not in the film or went by so fast I missed them. Kang? Mrs. Krabappel? Many favorites get minimal time: Mr. Burns gets one great line in his brief appearance; Apu gets less; and Groundskeeper Willie is M.I.A.

In short, it is hard to imagine fans being disappointed — or anyone else, for that matter. This shouldn’t come as a surprise, given the amazing amount of first-rate work the same filmmakers have managed to turn out on a weekly basis for nearly two decades.