★★

The LEGO Ninjago Movie is the second spin-off of 2014’s hit The LEGO Movie to come out this year (the first being The LEGO Batman Movie). The LEGO Movie was a surprising favorite among critics and audiences due to its ironic humor and imaginative visuals, while The LEGO Batman Movie proved a welcome parody of Christopher Nolan’s often humorless Dark Knight trilogy. In this latest installment, the LEGO franchise moves to the fictional city of Ninjago, which includes such vaguely Asian imagery as a giant dragon, pagodas, and a ninja master voiced by Jackie Chan.

Regardless of their content, the success of these movies largely depends on how much you’re able to buy into the whole LEGO aesthetic. It might seem like a hard sell at first, but when audiences are already used to digital images composed of millions of pixels, maybe seeing an animated movie made up of LEGO blocks isn’t that unusual after all. Plus, having the screen filled with the trademarked toys has a visual effect similar to playing an old Nintendo game -- the style may give some parents a twinge of nostalgia, along with the feeling of knowing superiority that goes along with the films’ self-referential sense of humor.

Thankfully, for those who have trouble enjoying this unnatural visual style, The LEGO Ninjago Movie doesn’t go as far as its predecessors did in creating every component of its setting out of virtual LEGO blocks. But the story remains largely the same: An evil tyrant is plotting to take over the world (in this case, the city of Ninjago), and our hapless protagonist is the only one with the power to stop him. And, as in The LEGO Movie, the film’s central conflict ultimately lies in the troubled relationship between a young boy and his father. Throw in the generic message that we all contain great power inside of us, and you have another inoffensive story that’s sure to keep kids occupied for an afternoon while selling tons of LEGO tie-in products over the upcoming holiday season.

Don’t worry, there’s still plenty of ironic humor to keep parents mildly amused, along with the opportunity to hear actors like Justin Theroux, Fred Armisen, and Kumail Nanjiani giving spirited voice performances. And kids who are into ninjas will certainly be intrigued. But while the story frequently references martial-arts philosophy and classic Hong Kong kung fu flicks, there are few actual scenes of martial-arts action in the film. Rather, its “ninjas” are more like a cross between superheroes and Transformers: They’re unpopular high schoolers who become machine-like warriors based on the elements in order to fight the evil Garmadon (Theroux).

So, despite a few improvements over the previous LEGO films, The LEGO Ninjago Movie makes the unfortunate mistake of underusing its key selling point -- the promise of cool ninja action inspired by vintage martial-arts flicks. Jackie Chan gives a typically enthusiastic performance as Master Wu, the young ninjas’ mentor and guide (he also plays an antiques-store owner in the clever framing device), but there’s still not enough substance here to give the film much staying power. For all but the most ninja-obsessed kids, The LEGO Ninjago Movie is probably destined to be forgotten after its theatrical run, thrown into the bargain bin to make way for a new merchandising franchise once the LEGO series has finally run its course.