Written by Seth Grahame-Smith, Chris McKenna, Erik Sommers, Jared Stern & John Whittingham.
Directed by Chris McKay.
This is a tail-eating meta-feast of pop-culture jokes and superhero cliches. It's like the Naked Gun for kids.
Will Arnett is back as (deep-voice) Batman. He kicks butt and can beat all of his arch-enemies at once. (We even get Calendar Man!) He life gets turned upside-down when he absentmindedly adopts Dick Grayson. Meanwhile, the Joker decides he needs better villains around him, since he and Riddler and Two-Face and Bane and Poison Ivy and... Condiments Man... are too easy to defeat.
Plot doesn't really matter (though it is fun). It's all about deconstructing what makes Lego Batman tick. There are a ton of cameos (everyone from King Kong to the Wonder Twins), and if anything I'd say the movie is too overstuffed. I was amused at quite a few of the gags, which is the main point and therefore the most important point.