The new sequel to The LEGO Movie is devoted to the idea that no Batman is an island.

Everything is lonesome for the title character in The LEGO Batman Movie, one that finds the famously grim and reclusive Caped Crusader (voice of Will Arnett) undergoing an improbably funny process of self-examination and growth.

An early scene finds him winding down after a long day fighting crime, watching Jerry Maguire on his home theater (even superheroes must scroll through the endless array of HDMI inputs to find the proper slot), a cavernous place that potentially seats about 50 but has only ever seated one -- Bruce Wayne/Batman.

It's an amusing visual joke, and a telling one – Batman is a work-obsessed, shallow, and isolated fellow who doesn't realize he's seeing his own reflection in Maguire.

The rest of the movie functions as a kind of LEGO Jerry Maguire, plotwise -- Batman adopts an orphan who becomes Robin (Michael Cera) and develops a crush on the police commissioner's daughter, Barbara (Rosario Dawson). Both relationships tease out threads of humanity in Batman, and the movie has fun contrasting analytics-expert Barbara with the hero's old-school approach, communicated via Batmansplaining.

The most complicated and rewarding bit, though, involves Batman's "relationship" with the Joker (Zach Galifianakis), who can't abide that Batman grants him no special status among villains, and pursues him like a jilted psycho in a Lifetime stalker movie, demanding that Batman admit that he hates him more than he hates the other bad guys. Add the ongoing Jerry Maguire motif, and you've got a disarming spin on the "you complete me" Batman-Joker dynamic.

The LEGO Batman Movie is an overdue corrective to the self-seriousness that sinks so many comic-book adaptations, most recently the lugubrious Batman v Superman (spoofed here), a movie that seemed determined to drain all joy from the idea of superheroes.

LEGO Batman puts some of it back, and with an astute super-fan's understanding of the entire Batman canon, both on screen and on the page. Half the jokes I didn't even get but could enjoy vicariously via the laughs of the geeked-out preview audience.

The movie functions as an affectionate Hollywood house satire of the genre -- one of the most consistently inventive since Airplane! (Surely I must be joking, I'm not joking, and stop calling me Shirley -- although I have a can't-help-it weakness for Hot Shots!, even Part Deux.)

This actually takes a certain amount of spine for Warner Bros., which presumably has commissioned more mopey Batman and Superman movies. The payoff for the studio can be found in the way the LEGO format allows it to playfully (and profitably) invoke all of the intellectual property it now controls – characters turn up from Harry Potter and King Kong.

LEGO Batman is not quite in the same league as The LEGO Movie – it's often content to be a  gag reel (with a few duds) and lacks the sly, dystopian commentary of the original – but it succeeds in its own way, and shares with The LEGO Movie the idea that the simple fun we found in the things we loved as children is worth preserving.