It would be silly to pretend that "Avengers: Age of Ultron" isn’t good at what it does, that it’s not proficient at delivering superhero thrills for those who crave them most.

‘Avengers: Age of Ultron’ Rated: PG-13 Opens Friday

With a budget of $250 million, a surfeit of stunts, explosions and computer effects, not to mention a checklist of Marvel Comics champions that includes Iron Man, the Hulk, Thor, Captain America, Black Widow and Hawkeye, this "Avengers" definitely does not go the minimalist route. (It even throws in a couple of characters named Maximoff for good measure.)

As written and directed by the skilled Joss Whedon, this Avengers movie even has, in its namesake Ultron, a convincingly twisted villain played by James Spader. Sounding uncomfortably presidential in his search for "the power to make real change," Ultron wants to destroy the world and kill everyone in it for the best possible reasons.

But even as all these good things are acknowledged, the uncomfortable reality remains that although this movie is effective moment to moment, very little of it lingers in the mind afterward. The ideal vehicle for our age of immediate sensation and instant gratification, it disappears without a trace almost as soon as it’s consumed.

Given that the Marvel movies are, in effect, expensive Saturday matinee serials, bringing back the same familiar characters time after time after time (this is, for instance, the fifth film in which Robert Downey Jr. has starred as Iron Man), that lack of staying power is perhaps inevitable. It’s the brand, finally, not the individual episodes, that matter most to the powers that be.

Whedon, whose first Avengers movie was more appealing in part because his sensibility was fresher, works very hard to compensate for this over-familiarity in big ways and small. Even the Avengers’ weaponry, the press material informs us, has been "tweaked," with Captain America (Chris Evans) getting a shield with a boomerang effect and Hawkeye (Jeremy Renner) acquiring an automated quiver ideal for the swiftest possible loading of arrows.

Whedon’s dialogue writing is also a plus, and not just for the clever lines he comes up with. There may be no one else who would or could fit amusing references to Banksy, Eugene O’Neill and how hard it is to afford a place in Brooklyn into a superhero epic.

The filmmaker also tries to make up for character familiarity by taking advantage of Marvel’s penchant for superheroes with complex psyches and, for instance, amping up the potential for romance between the troubled Bruce Banner/the Hulk (Mark Ruffalo) and Black Widow (Scarlett Johansson).

And, knowing that Marvel audiences hunger for fresh blood just as much as the vampires in "Twilight," he has given space to those Maximoffs, the twins employed by the evil empire Hydra to battle the Avengers and usually known by their superpower names. Pietro Maximoff (Aaron Taylor-Johnson) is the superfast Quicksilver and sister Wanda (Elizabeth Olsen) is Scarlet Witch, characterized by the ability to cloud men’s minds.

Where this Avengers movie is at its weakest is in its plot. Well-made though each action sequence may be, there are so many of them, including more going on in the precredits sequence than in many entire films, that everything blurs together. One may remember the Hulk went on a rampage in Johannesburg, South Africa, of all places, but there have been so many rampages in so many movies that reasons and motivations get lost in a frenetic, undifferentiated heap.

Whether this is what fans ravenous for nonstop stimulation want, what Whedon prefers or what the Marvel hierarchy mandates, all this action overloads the senses. When you add in a bloated running time of two hours, 22 minutes, what happens on the screen stays on the screen and is difficult to recall later on.

That’s a shame, because it detracts from Ultron, one of the most memorable of Marvel movie villains and an entity impossible to confuse with anything else.

Before we meet Ultron, the Avengers raid a Hydra redoubt in the conveniently fictional country of Sokovia. There they recover Loki’s powerful scepter, which had somehow fallen into the hands of the evildoers.

Back in the U.S. of A., where the Avengers have their own skyscraper, complete with an enormous logo, Tony Stark (Downey) gets the unfortunate idea to clandestinely use the scepter to create Ultron, a creature of artificial intelligence he intends to function as a global peace-keeping apparatus.

But, wouldn’t you know it, wires get crossed and Ultron gets everything mixed up. "I know you mean well, but you haven’t thought it through," he tells the overmatched and befuddled Avengers. "There is only one path to peace: your extinction."

Beautifully voiced and brought to life by Spader in a motion-capture suit, Ultron is eccentric enough to do things like singing "there are no strings on me" when he initially breaks free of Stark’s control. Ultron is certainly a memorable creation, which is not always what you can say about the film that brought him to life.

Review by Kenneth Turan, Los Angeles Times