We’re nearly an hour into “Pixels” before we get a good look at the arcade video game-inspired attackers that have invaded Earth and are gobbling up humans and famous landmarks alike.

That’s a problem, because this ain’t “Jaws.” Pac-Man isn’t as threatening as a giant shark, and Adam Sandler, Kevin James and Josh Gad aren’t Roy Scheider, Richard Dreyfuss and Robert Shaw. We’re dealing with a ridiculously goofy premise in the first place, so why not just get to the silliness quickly rather than wasting 50-plus minutes giving us a typical Sandler comedy with cheap laughs, a few genuinely funny moments and a lot of filler?

This isn’t a terrible movie. It just seems like a clever sketch stretched to feature film length. (Indeed, “Pixels” is based on a 2010 French animated short by Patrick Jean.)

Directed by Chris Columbus (“Mrs. Doubtfire,” “Home Alone,” a couple of the “Harry Potter” movies), who has a long track record of mixing comedy and action to winning effect, “Pixels” has a few inspired action sequences and a handful of laugh-out-loud moments, but overall, the special effects are surprisingly average – and the lazy acting by Sandler, the shameless mugging by James and the hammy performance by Brian Cox don’t help.

Not even Peter Dinklage in a mullet can save the day.

In an extended prologue set in 1982, 13-year-old Brenner (Anthony Ippolito) and his best friend, Cooper (Jared Riley), ride their Stingray bikes to the newly opened video arcade, where Brenner instantly establishes his mastery of such games as Pac-Man, Centipede, Tetris and Space Invaders. (Cooper’s more suited to that game where you lower the claw into a batch of prizes and try to snatch one up.)

Cut to present day, where Cooper (James) is now the buffoonish, dopey and extremely unpopular president of the United States, while Brenner (Sandler) is a sad sack who wears a stupid orange uniform and installs TVs and video games. Seems Brenner never got over his defeat at Donkey Kong at the hands of the showboating Eddie (played by Dinklage as a grown-up), and geez, Brenner, how about getting over it? As if having been champion of an arcade competition when you were a kid is so much more amazing than having finished second.

Michelle Monaghan is Violet, a soon-to-be-divorced mom who is a high-ranking weapons specialist for the government. (Sure, why not.) Cox is an unhinged, warmongering admiral. Jane Krakowski is the first lady. Gad is Ludlow, a creepy but somehow lovable gamer and conspiracy theorist who lives in his mom’s basement, naturally. (My favorite of Ludlow’s conspiracy theories: The Zapruder film was edited to delete the segment showing JFK shot first.)

So why are aliens using 1980s video games as weapons? Thought you’d never ask. Back in 1982, NASA sent a time capsule into space that included video feeds of classic arcade games. The aliens misinterpreted the videos as a declaration of war, and for some reason decided the best plan of attack would be to re-create Pac-Man, Galaga, Donkey Kong, Centipede, etc., and send them down to Earth to destroy the planet.

That’s pretty much the deal. President Cooper rounds up the old gang because who better to play a real-life game of Space Invaders in the sky than the nerds who mastered it back in the day?

The interaction between the humans and the CGI invaders lacks depth and texture, even in the 3-D version I saw. At times, it’s painfully obvious Sandler and company are looking at whatever the heck they were looking at when the movie is trying to persuade us they’re blasting Pac-Man to bits or quipping with Q*bert.

Dinklage scores some laughs and Sandler tosses off a funny insult here and there, but has zero chemistry with Monaghan as his potential love interest. Visual gags featuring familiar 1980s icons fall flat for the most part.

It appears Columbus was going for a “Ghostbusters” feel, complete with scenes of the gamers becoming instant celebrities in New York as they do battle with mysterious forces in the sky. “Pixels” is devoid of cynicism and it has a cheerfully cheesy vibe; it’s the kind of movie you’ll forget about a week after seeing it. Rated PG-13.