"Monsters vs. Aliens," now at your local cinema, is a stroll down memory lane — minus the horror — to  the sci-fi phenom of those 1950s-'60s B-movies.

Think about it: the animated newbie, with 3-D options to enhance and jack up interest for the youngsters, introduces a blue blob named B.O.B. (think "The Blob," circa 1958); a swamp-originated amphibian named The Missing Link (think "Creature From the Black Lagoon," the 1954 flick that featured the late local actor Ben Chapman as The Gill Man, aka The Creature) and Dr. Cockroach (think any flick with crawling roaches).

The mood is gentle spoofery; the tone is family-friendly. But echoes of the monster mashes and bashes of the past resonate.

Add a superduper-sized heroine named Ginormica (aka Susan, before a meteor crash turns her into the gigantica babe just short of 50 feet), and you'll track footprints back to those Japanese battling monsters like Mothra and Godzilla, albeit with a feminist update.

Like "Attack of the 50 Foot Woman," circa 1958, which was a takeoff of  "The Amazing Colossal Man," from  1957, and you'll agree — everything old is new again.

"Monsters vs. Aliens" retells the prevailing fear we all have of species we don't understand because misfits look different and behave strangely. The film doesn't aspire to be "Close Encounters of the Third Kind" or "E.T.," storytelling, which had both empathy and fear in their lessons of understanding whatever is Out There, but "MvA" aims to have fun in channeling these sci-fi critters who share what might be termed the "Wizard of Oz" sensibility with "Independence Day" doomsday philosophy: to find the courage, heart and brain of who you are in a world that doesn't always have a yellow brick roadway to separate who's monster, who's alien.

"Monsters vs. Aliens" is more of an excuse to launch an assembly-line of new toys and video doohickeys for the product-spinoff generation. Or worse, a theme park attraction.

This confection, from DreamWorks (the studio that brought us "Shrek," "Kung Fu Panda" and "Madagascar"), is high on gimmick with marginal storyline. Extraterrestrial types invade; bizarre but friendly creatures, hidden in an underground prison, do battle and, well, become heroes. And who doesn't adore heroes? An exceptional sequence involves a crumbling Golden Gate Bridge.

And the 3-D effects — a pingpong ball looping into the audience, space debris tumbling from the skies — provide predictable diversions.

Susan (voiced by Reese Witherspoon) is the Dorothy of this space oddity, a bride-to-be of Derek (Paul Rudd), a jerk of a TV weatherman, who, on her wedding day, is exposed to meteor debris (twisters and tornadoes are so yesterday) and becomes Ginormica, a lady Paul Bunyan roped and anchored like Gulliver because of her enormity.  She is sent to an underground enclave where other peculiar species are imprisoned: B.O.B. (Seth Rogen), Dr. Cockroach (Hugh Laurie) the Missing Link (Will Arnett), and Insectosaurus (no celeb status here).

The kids will adore the cuteness of these mutants; the adults will applaud some of the casting — like Stephen Colbert getting his due as the U.S. president, and Rainn Wilson as Gallaxhar, a hydrant-shaped creature with tentacles, who is the antagonist in the interplanetary angst, eager to claim Ginormica because of space-related elements  that made her humongous and — whatever the implications — are the key to world domination.

And, as General W.R. Monger, Kiefer Sutherland shows he's in control 24/7.

All of this is not rocket science, but if you go, see this one in 3-D — it maximizes the enjoyment; the added dimension continues to be an emerging avenue of ramping up admission.

Too bad the filmmakers didn't go overboard to encompass a cutesy tune like "The Purple People Eater" or "Witch Doctor" to give the movie a sing-along hit song, too, to play off the characters from the film.

Or even go spacey like  Dickie Goodman's "The Flying Saucer" musical montage of 1956 — now, that novelty was a blast from the past, wasn't it?

You're really savvy if you can name the oldie-goldies assembled in "The Flying Saucer." C'mon, give it a try ...