Diary of a Wimpy Kid should've been titled Diary of a Selfish, Dishonest Punk. That's not exactly a knock against the kid-friendly comedy, directed by Thor Freudenthal from the best-selling series of books by cartoonist Jeff Kinney. It's just an observation. Greg Heffley (played by Zachary Gordon) is almost like the Larry David of the junior high set -- scheming, self-absorbed, prone to lying and manipulating situations to get his own way. I have no idea if that's how Kinney characterized Greg in the books, but it makes for a unique protagonist for a family film. I'm accustomed, through a lifetime of movie-watching, to seeing good kids become social outcasts through no real fault of their own. Diary of a Wimpy Kid's Greg is so selfish that everything that befalls him feels like karmic retribution.
I don't think that's a weakness; that's just the way it is here. Not to spoil anything, but even Greg's big opportunity for a selfless, redeeming act at the film's finale has him lying to everyone at his school, then literally calling them all stupid. The strange thing is that the filmmakers seem unaware of the character they've created on screen, something akin to watching The Wonder Years if it starred Eric Cartman instead of Kevin Arnold.
While I don't really feel like Greg's questionable morals hinder the film, the screenplay's rambling, episodic approach doesn't help it. The movie is about Greg's desire to climb a junior high social ladder of his own creation, a 1-to-200 ranking system where he sees himself in the top twenty, and his best friend Rowley (Robert Capron) hovering around the bottom fifty. This means of course that he'll gladly tromp all over his relationship with his best pal in order to appear cool to a bunch of people he doesn't even really know, taking part in a series of extracurricular activities that he's in no way suited for.