Review in a Hurry: Rodrick (Devon Bostick) does indeed rule, but not over much: As bad-boy big bro to the eponymous Wimpy Kid, he's the only fully developed character in a thrown-together sea of stock types. Bostick potentially has a bright future ahead, but the franchise doesn't...creatively, anyway.
The Bigger Picture: In a children's book, you can get away with highly episodic structure, as each chapter can be its own story. Try to do that on film, and you get something that feels like an attempt at a PG Family Guy, all tangents and irrelevant asides and substantially less funny than the Griffin clan. Turning the black and white cartoons of Jeff Kinney's books into gaudy, artificially colored production design also feels like a mistake, but audiences know where they stand at this point. (Why do so many kiddie flicks use bright colors even when they feel unnatural and look like vomit?)
There's something almost resembling a plot here about a town talent contest, but it's mostly forgotten about until enough minutes have elapsed that we need an ending. Before then, the story is just a series of short events in which Rodrick and wimpy Greg (Zachary Gordon) go from enemies to unlikely buddies and back again—then back again...again. Chloë Moretz wisely opted not to return for this sequel.
For no particular reason, Greg decides to ignore his Indian stereotype friend (Karan Brar), engages in poorly staged slapstick that involves elderly ladies in a restroom and tries to make a funny YouTube video. Meanwhile, mom (Rachael Harris) tries to bribe Rodrick into hanging out with Greg more, and dad (Steve Zahn) acts like a dork. The soundtrack tries to keep us alert by constantly shifting from one generic pop tune to the next (including a bland cover of that end-credits calypso song from Beetlejuice), but it feels not unlike an annoyingly hyper morning person is irritatingly trying to nudge us awake from sweet stupor.
It's hard to blame the actors, as they are quite literally playing stick figures. Only Bostick seems to actually care about the material enough to transcend it, and we hope for his sake that this eventually becomes a mere footnote in what should be a long career.
The 180—a Second Opinion: As much as any sane person may hate to admit it, Rodrick's band, Lodid Diper, performs a final number called "Exploded Diaper" that is way catchier than expected.