Chris Hemsworth and Anthony Hopkins in “Thor.” (Paramount)

The summer movie season has arrived, in the form of an in­cred­ibly cut hero from another realm who carries an excessively heavy hammer.

Which is another way of saying that “Thor” opens in theaters today, officially launching 2011’s popcorn-cinema period. But is it worth seeing?

The 80 percent positive rating on Rotten Tomatoes suggests yes. Here’s a roundup of some critical assessments — including one from The Post’s Michael O’Sullivan — followed by my personal take on the 3-D comic book movie that Kenneth Branagh built.

Michael O’Sullivan of The Washington Post — otherwise known as this here publication — notes that “Thor” is not for everyone, especially those who don’t care much for comic book movies. “If, on the other hand, you have a fondness for loud, silly, eye-popping action adventure films based on beloved superhero characters — or even superhero characters who are appreciated with the cool, clinical detachment of a student of pop culture — then ‘Thor’ delivers,” he writes.

A.O. Scott of the New York Times finds the movie depressingly adequate. “Mr. Branagh has not failed to make an interesting, lively, emotionally satisfying superhero movie, because there is no evidence that he (or the gaggle of credited screenwriters, or Paramount, the sponsoring studio) ever intended to make any such thing,” he writes. “On the contrary, the absolute and unbroken mediocrity of ‘Thor’ is evidence of its success. This movie is not distinctively bad, it is axiomatically bad.”

Michael Phillips of the Chicago Tribune doesn’t care for the movie’s beginning or end, but he likes the ooey-gooey center: “The last 25 minutes of ‘Thor’ aren’t much better than the first. But that hour in between — tasty, funny, robustly acted — more than compensates.”

Amy Biancolli of the Houston Chronicle gives “Thor” three stars. And while she finds the 3-D pointless, she does appreciate the sensitive caveman approach of leading man Chris Hemsworth: “Hemsworth, whom geeks will recall as Kirk’s dad in J.J. Abrams’ ‘Star Trek,’ is as likable as he is large, a booming blond hulk with twinkly eyes and passable comic timing.”

Owen Gleiberman of Entertainment Weekly has an even more glowing review: “‘Thor’ . . . pulls off something I wouldn’t have thought possible: It restores the innocence to big-budget superhero mythmaking.”

As for my reaction? I fall more in the A.O. Scott camp. There are two things about “Thor” that may stick in my memory: that Chris Hemsworth has the biceps of an otherworldy weight lifter and that the film’s frost giants reminded me a lot of the Snow Miser. The rest? It will probably fade into a CGI-generated mist before the weekend is up.

As epic as “Thor” wants to be, ultimately it just feels generic. As someone who wasn’t already super-invested in the comic, I couldn’t muster the energy to care much about the characters.

I am someone who likes a really good comic book movie. But to me, “Thor” wasn’t a really good comic book movie. Of course, that undoubtedly won’t stop it from raking in millions at the box office.

When Marvel throws down a hammer, no matter what the critics may say, moviegoers are likely to pay attention.