This is the most purely entertaining film of the year, a joyous space romp that all but explodes off the screen with lots of action and even more charm.

Our recent superheros have been complex, often anguished, even downright tortured. It has been a while since we’ve had a charming rogue with a bad attitude but a hero’s heart. Enter Peter Quill (Chris Pratt), who keeps trying to get people to call him Star Lord and who carries with him on his interplanetary space travels the “awesome mixtape” he was listening to as a young boy on Earth back in the 1980’s, when his mother died and a spaceship came to suck him up from the ground and take him far, far away.  One of the purest pleasures of the film is the soundtrack of 70’s gems like “Ooh Child,” “Come and Get Your Love,” and “Hooked on a Feeling” (the ooga-chacka Blue Swede version) and some others too delicious to give away, wittily juxtaposed with spaceships and aliens.

In a scene that pays homage to the classic opening of “Raiders of the Lost Ark” and with a personality that owes a lot to Harrison Ford’s irresistible space rogue Han Solo, Quill enters a chamber and steals a precious orb from a pedestal, only to be stopped by Korath (Djimon Hounsou) and some other scary-looking guys with sci-fi gun-looking things.  A lot of people want the orb and are willing to take extreme measures.  Evil wants-to-control-the-galaxy guy  Ronan (Lee Pace) sends the beautiful but deadly green assassin Gamora (Zoe Saldana, who seems to specialize in colorful space characters) to get it.  Also interested are superthief Rocket Racoon, a genetically modified procyonid (voiced by Bradley Cooper) and his sidekick Groot, an enormous, self re-generating talking tree (voice of Vin Diesel).  Groot can only say one existential sentence, but it is remarkably expressive.  Then there’s Drax (Dave Bautista), who just wants to destroy pretty much everyone, but especially Ronan, who killed his family.  He is completely literal, with no capacity to process metaphor (except when the script calls for him not to be, but no need to get overly focused on consistency here).

This motley crew ends up in prison together, where they form a bond through an elaborate escape plan and a lot of quippy dialogue.  The  low-key, unpretentious “Bad News Bears”/”Dirty Dozen” vibe is refreshing after so much sincerity and angst in the superhero genre. It hits the sweet spot, irreverent without being snarky. And because it is set away from earth we are spared the usual scenes of destroying iconic skylines and monuments.  Instead we get a range of richly imagined exotic settings and wild characters, though Lee Pace is under too much make-up and is stuck with a one-note character as Ronan.  It is a shame that the bad guy is not as delightfully off-kilter as the good guys, but with five of them, there is plenty to keep us entertained.  I don’t want to get too picky (see consistency note above), but the orb’s purpose and powers don’t seem to be thought through too well, either.  I don’t ask for much from a McGuffin, just that it (1) propel the storyline and (2) not interfere with the storyline.  This one doesn’t quite meet #2.

But deliciously entertaining it still is, with a long-overdue star-making role for Pratt, who has been the best thing in too many second-tier movies and outstanding but under-noticed in top-level films like “Moneyball” and “Zero Dark Thirty.”  Director James Gunn, who also co-scripted with first-timer Nicole Perlman, has made the summer popcorn movie of 2014, tremendous fun, and with more heart that we have any reason to expect.  Can’t wait for the just-announced part 2.

Parents should know that this film has extended (and quite cool) science fiction/comic book/action-style peril, violence, and action with fighting and various weapons, some characters injured and killed, some disturbing images, some sexual references, and some strong language (two f-words).

Family discussion: What makes this group especially suitable for taking on Ronan? How does this movie differ from other superhero/comic book films?

If you like this, try: “Men in Black” and “The Avengers”