In theaters

SERENITY, written and directed by Joss Whedon, 119 minutes, rated PG-13.

Joss Whedon’s first feature-length film, the sci-fi powerhouse “Serenity,” is designed to exist on its own terms, which it does, without apology. And that’s a good thing.

This lively, visceral film takes stock Asian, sci-fi and Wild Western elements and twists them into an intergalactic space adventure that somehow escaped being tweaked to serve the masses. It’s for hard-core sci-fi fans, and as such, it likely will become an underground hit.

Those drawn to it will find a tricky balancing act at hand, with humor, pathos, drama, wit, action and fear all roiling in the caldron of Whedon’s rich hybrid of an imagination. Here is a writer-director who is so confident in his craft – and whose vision is so steeped in pop culture lore – that he’s able to toy with the references without slavishly adhering to the formula that normally drives them.

From Whedon’s script, “Serenity” is based on the director’s ill-fated, 2002 Fox television show, “Firefly.” If, like me, you never saw an episode, be prepared for an anything-goes thrill ride here.

Set 500 years in the future, the film follows Mal Reynolds (Nathan Fillion), brawny captain of the junk spaceship Serenity, whose crew is a melting pot of capable misfits facing a civil war that involves a band of zombie cannibals, scientific experiments gone awry and the Alliance, which naturally wants control of the universe.

Spearheaded by an unnamed assassin played with steely reserve by Chiwetel Ejiofor, the Alliance is aggressively seeking River Tam (Summer Glau), a telepathic wreck who knows things about the Alliance that the Alliance would rather keep secret. Really secret. So secret, in fact, that they will kill anything and anyone in their path to make sure this River is dammed shut.

Problem is, River is a martial-arts genius with anger management issues who is having none of that. Neither is anyone aboard the Serenity, which makes for a movie that becomes impressively intense as it veers toward an ending whose climax isn’t telegraphed. There are genuine surprises here, particularly at the end, which gives this swift movie a formidable kick.

What you admire in “Serenity” is Whedon’s nerve – one false move, and this deceptively fragile film, with its deceptively sturdy facade, could have collapsed if just the right tone wasn’t struck. And yet it is struck. Whedon’s ability to shift between elements of horror and humor is exactly what he did so well in the television series he created, “Buffy the Vampire Slayer.”

As a director, he recalls a young George Lucas before the dark side of marketing, industry and special effects got the better of him. Still, Whedon owes a debt to Lucas. Since so much of “Serenity” relies on the guts of the “Star Wars” franchise, it’s unlikely that it would even exist without the vision Lucas had when Whedon was still a boy, presumably playing with all those “Star Wars” toys.

Grade: A-

On video and DVD

UNLEASHED, directed by Luis Leterrier, written by Luc Besson, 103 minutes, rated R.

Luis Leterrier’s “Unleashed” was released in France under the title “Danny the Dog,” which gets right to the point. The movie is a howler.

As directed by Leterrier from a script by Luc Besson, “Unleashed” stars Jet Li as a confused, embattled orphan named Danny who is raised by his brutish Uncle Bart (Bob Hoskins) to be nothing short of a killer dog. That’s the good news.

At 42, Li still is nimble, still clever behind the kick. His blows are precise, elegant, deadly. It’s when he’s called upon to act that things get deadlier.

Essentially, this story of hard luck and woe is an action movie weepy, which sounds every bit as misguided as it is, particularly since neither Leterrier or Besson is exactly a poet when it comes to plumbing one’s tear ducts. After a violent start, the movie sags into marshmallow land with cutesy-pie scenes of awkward character building, the likes of which can be repellantly heartwarming as Li is set adrift within them.

Set in Glasgow, the film follows Danny as he breaks free from his life of crime with Bart and comes to live with an adoptive family – Morgan Freeman’s Sam, a blind piano tuner, and his stepdaughter, Victoria (Kerry Condon), who is studying music. Aware that they are dealing with a fragile soul – the metal collar cinched around Danny’s neck is something of a giveaway – Sam and Victoria allow him the room he needs to breathe while he sorts out his life.

He won’t have long to do so. Seething in the subplot is Bart, who has worked up a sweat in his ferocious vow to get Danny back regardless of the blood shed and the lives lost. Meanwhile, Danny is a naif in utopia, flirting with Victoria over ice cream while working to reconnect with the world. What he finds are revelations about his mother – painful – the sort of dialogue that sets the movie on its can – atrocious – and the proper way to thump a melon – helpful. “Ripe means sweet!” Danny says as he taps a piece of fruit. “And sweet means good!”

If only that were true for the movie, Danny boy. Here, ripe means rot, sweet means cloying, and good doesn’t even come close to describing all that follows.

Grade: C-

Visit www.weekinrewind.com, the new archive of Bangor Daily News film critic Christopher Smith’s reviews, which appear Mondays in Discovering, Fridays in Happening, and Weekends in Television. He may be reached at Christopher@weekinrewind.com.

THE VIDEO-DVD CORNER

Renting a video or a DVD? BDN film critic Christopher Smith can help. Below are his grades of recent releases in video stores. Those in bold print are new to video stores this week.

The Adventures of Sharkboy & Lavagirl In 3-D – D-

Alexander – C

The Amityville Horror – C-

A Very Long Engagement – A

The Aviator – A

Bad Education – A

Beauty Shop – C-

Bride & Prejudice – B

The Brown Bunny – C

Constantine – C-

Crash – D

Cursed – C-

Desperate Housewives: Complete First Season – B+

The Devil’s Rejects – B

A Dirty Shame – B

Ella Enchanted – B

Fever Pitch – A-

Flight Of The Phoenix – C-

Guess Who – C+

Hammer Horror Series – A

Hide and Seek – C

The Hitchhiker’s Guide to the Galaxy – B-

House of D – D

House of Flying Daggers – A

Inside Deep Throat – B+

Ice Princess – B-

The Interpreter – B+

Kingdom of Heaven – B-

Kung Fu Hustle – A

Ladder 49 – B

The Longest Yard – C

A Lot Like Love – D

Million Dollar Baby – A

Miss Congeniality 2: Armed and Fabulous – C+

Monster-in-Law – B-

Muppet Show: Season One – A

The Notebook – B+

Ray – A

Scary Movie 3.5 – B

The Sea Inside – A-

Sin City – A-

The Sisterhood of the Traveling Pants – B

Upside of Anger – B

Unleashed – C-

Vintage Mickey – B+

The Wedding Date – B