Diary of a Wimpy Kid is sweet and funny at either end, but in between, it sags with endless repetition of gross bodily functions and Greg's torment at the hands of larger, angrier, or more popular kids -- in that order.
The casting's pretty fair, and if they had better material, Steve Zahn and Rachael Harris would have been real assets. But the story lurches from indignity to ill-starred wrestling match to gross-out gag, without any momentum or surprise.
Between the episodic scenes that have no punch, and the lethargic direction in which children could grow a shoe size in the yawning gaps from one line to the next, the best word for this tedious project may very well be "Wimpy."
Greg's not wimpy--he fears being a pussy. This apparently gives him licence to be a total dickhead. The film should be retitled Diary of a Sociopathic Kid . . . it offers a cynical, shrugging view of today's tweens.