Skyline, in which an army of airborne aliens comes up with the novel idea of storming Los Angeles in search of fresh human brains, shatters the unintentional comedy scale with its clunky dialogue and laughably straight-faced treatment of B-movie schlock.

As a showcase for brothers Colin and Greg Strause, visual-effects specialists with a single directorial credit to their names– the middling Aliens vs. Predator: Requiem (2007) – the film confirms their ability to create a diverting spectacle on a limited budget, but speaks little to their storytelling acumen.

Whether the Strauses are capable to spinning a yarn with the same enthusiasm and obvious care they bring to their CGI handiwork is anyone’s guess, but here they are spinning their wheels with a cynical mash-up of ideas more imaginatively explored in various incarnations of H.G. Wells’ War of the Worlds and last year’s District 9.

In the early morning hours, Jarrod (Six Feet Under’s Eric Balfour) and his pregnant girlfriend Elaine (Scottie Thompson) are awakened by dozens of brilliant, electric-blue lights descending from the sky and luring stunned onlookers to their ethereal glow. Within seconds, the poor saps are vacuumed onto a mother ship where reptilian butchers will suck down their brains like Slurpees.

Jarrod and Elaine aren’t so lucky. They survive long enough to wage a 90-minute resistance from inside a Marina del Rey condo, flanked by a small, quarrelsome crew of doomed survivalists, including special-effects guru Terry (Donald Faison, of TV’s Scrubs) and a security guard (Dexter’s David Zayas) bent on playing the hero.

Their strategy, which includes taking refuge on the roof (bad idea) and later in the parking garage (worse), defies imagination and strains logic. Jarrod wants to flee the city. Elaine prefers to hide in the penthouse with the blinds drawn. “Everything is under control!” bellows Terry, brandishing his gun and morphing into a disaster-movie cliché.

So far, so familiar, but if Skyline never seems interested in pushing the envelope, it at least begins with enough promise to suggest a competent thriller. No such luck.

As evidence that $10 million can buy some fine-looking monsters, creepy enough to make us recoil, Skyline is an unqualified success. Not included are more vital accessories – compelling twists, thoughtful dialogue and characters distinguishable as something more than an ornery extraterrestrial’s next meal. Maybe the aliens got to them first.