Marvel’s “The Avengers” arrives in theaters  and fanboys are having multiple geekgasms online. Message boards are lit up over at the imdb. At rottentomatoes, no turn is being left unstoned, with nerds savaging the few bad reviews and even going after many of the good ones they feel give away too many plot points and too many of the film’s many wonderful one-liners.

No one is getting it worse than Richard Corliss over at Time, in what might be the most thoughtful piece of writing online about the film as the critic documents every essential detail in the movies that culminate into the superhero mash-up that is this one. It’s a perfect historical essay for anyone who hasn’t a clue about this set of comic book heroes or the recent movies made about them in the Marvel series. I highly recommend it for anyone out there who really wishes to give a darn that two of the main characters are demigods from Asgard and that one of them has recently acquired the Tessaract, which is essentially this movie’s “MacGuffin“, and squared at that: it serves the dual purpose of being a renewable source of eternal energy for whoever has it along with being a nifty portal into the cosmos.

And that’s where the discussion of plot will end with me, since it doesn’t really matter. The reason fanboys will end up seeing this movie is because it’s a high-octane event picture featuring a bunch of superheroes with quirky features facing off not only against a common threat, but against themselves in how they must negotiate the terms of their inclusion into the S.H.I.E.L.D. initiative meant to be the last resort on the planet where NATO or even the United States military is impotent to other-worldly dangers.

You non-fans will end up seeing it despite yourselves, the same way you got dragged to “Titanic” and “Avatar” before this, it’s just that big an event. Everywhere you go this weekend, any conversation you happen to eavesdrop upon relating to the movies will no doubt feature this one.

First, for the non-fans, all you need to know is that six Marvel superheroes join forces here in a project that’s been in the works for a few years now. There’s Robert Downey Jr.‘s self-obsessed and acid-tongued Tony Stark/Iron Man; Mark Ruffalo‘s brainy, inward Bruce Banner/The Hulk; Chris Hemsworth as the muscle-bound Thor; and Chris Evans, earnest and old-fashioned as Captain America. Those guys got their own origin movies before this one while this edition brings two characters to the forefront in Iron Man 2′s Natasha Romanoff/Black Widow (Scarlett Johansson) as well as Jeremy Renner (The Hurt Locker, Mission: Impossible 4) as S.H.I.E.L.D. Agent Clint Barton/Hawkeye.

This genre depends upon juicy villains, and Tom Hiddleston is back as Loki, the alternatively-sexy bad-boy brother of Thor, the kind of chap women date before they settle for Captain America.

Samuel L. Jackson returns as S.H.I.E.L.D. leader Nick Fury, and so too does Clark Gregg as Agent Phil Coulson. Cobie Smulders is an addition to that team, playing Agent Maria Hill, in a totally superfluous role where she is given the task of asking dumb questions all the time, as if any average person wouldn’t be able to follow what’s going on. For whatever reason, she is given plenty of screen-time while Gwyneth Paltrow as Pepper Potts appears in only two scenes. Go figure.

The screenplay, by writer/director Joss Whedon  (Serenity and Buffy the Vampire Slayer), from a story that originated from Zak Penn (of X-Men and Incredible Hulk fame) is at its best when it pits the assembling of its heroes against each other on a massive and magnificent aircraft. There is a palpable sense of giddiness running underneath the entire film in this section, and the laughs the movie generates with the use of observational humor are well-deserved.

Robert Downey Jr. is on fire here once again, providing the movie with a running dvd-commentary of-sorts, particularly in the rivalry he begets with the self-serious Captain America and Thor, but also in how he relates intellectually with Bruce Banner.

Those two are the sexy, high-profile ones. They’re constantly provided with terrific opportunities at humor at the expense of what I feel to be the two mid-tempo heroes in Captain America and Thor. They’re exploited for their earnestness, but I found that too often they are the butt of the joke in writing that never really allows them their moments to shine in the same way, and maybe that’s because (and here the fanboys will throw tomatoes and other things at me) their characters lack the mystery or the complexity of Iron Man and the Hulk. I’ve always felt Captain America is the lesser-than of Superman, and in this movie he displays fine acrobatic skills that simply pale in comparison to the gifts of some of the others. He’s got his trash-can-top-turned-superhero-discus but this movie doesn’t really exploit his skill-set so much while relegating him as the final act’s traffic cop to the other supers in the Manhattan finale.

As for Thor, his movie sucked, but I found he worked much better as a supporting character in this one. He’s essentially not anymore complex than if you were to imagine Bam-Bam from the Flintstones growing up to become the protege of Laurence Olivier, with his Mid-Atlantic dialect meant, I suppose, to lend him the same kind of respectability like that of a strip joint that serves meals. It’s still just a strip joint, and Thor is still just a Bam-Bam type despite his penchant for speaking in iambic pentameter as he smashes things up real good with that hammer that he can summon from just about any distance.

Jeremy Renner and Scarlett Johansson are used well here in the category of “humans who play dress-up”, who aren’t really supers themselves, but who are fleshed out with their own characteristics meant for us more average folk to relate to if we were able to be promoted to the ranks of superhero-helpers. Renner is a fine physical actor, and he’s involved in a terrific set-piece involving his skill at shooting arrows. Johansson is sexy-smart throughout and the screenplay does a great job of setting her up in two key scenes that show her at her intelligent best.

The revelation here is Mark Ruffalo as Banner, bringing to the screen the third rendering of this character in under a decade. When he’s not on-screen, you want him up there. His is the first Hulk that makes us believe there’s an actor inside the big green guy. The CGI here appears to capture in the Hulk some of Ruffalo’s characteristics, which was something lacking in the two previous Hulk movies. I was especially delighted at Thor’s last-act comeuppance at the hands of the Hulk.

Where director Joss Whedon gets it right is in the tone of the piece. He creates a movie that is winking at us the whole time, it’s tongue firmly planted in its cheek. I suppose I could complain about the final act and it’s reliance on a deus ex machina to wrap things up pretty tidily, as well as the boringly generic creatures that Loki unleashes from the cosmic portal in order so that all of the supers have something more to do than just hang out in Manhattan waxing philosophicalities and bumping egos with each other, but the movie by that point is having so much fun with itself that I was hooked. I was even able to distract myself from asking logical questions like, “If Loki can’t beat one Avenger in the movie he was in last year, what makes anyone think he can beat six of ‘em?”. But, there I go with plot again, and I promised I wouldn’t do that, because it matters not.

Marvel’s “The Avengers” is a movie comfortable within the confines of its Saturday-morning-serial feel than in transcending the genre the way Superman’s I & II, “The Dark Knight”, “Spider Man 2″, or “Iron Man” did. It’s high-energy and silliness distracts from the longer-than-average running time as well as sometimes the general feel of it being an origin story itself. It’s got dazzling effects and very good acting, sharply-observed writing, and even if the movie inspires more chuckles and smiles than real awe, the journey is well worth the ticket price. Good for the fanboys and appealing to the non-fans in equal measure.

Marvel’s “The Avengers” ***