****SPOILERS AHEAD***
If you've read the book, you come away from the movie disappointed. They attempted to create a children's fantasy movie when in fact the story is more aimed at teens, exploring young love, family dynamics, and dealing with unexpected tragedy. While the book also explored imagination, it did not go so deep into fantasy to actually create the stories that the movie did. The book has a more dark emotional sense, where as the movie is like "Chronicle of Narnia" getting dragged into it.
While the movie got the part correct where Jess goes with his teacher to the city, it completely ruined the way that he found out about Leslie. In the movie, Jess comes home to a mourning loving family who pulls him into the fold. In the book, one of Jess's sisters is the first one to speak as he returns from the city, blurting out "Your girlfriend's dead, and momma thought you was dead too". It cut straight to the bone, I will never forget that feeling, the wind knocked out of me, as the reader. I can think of very few books/stories that affected me the same way. Where The Red Fern Grows comes to mind, as does The Scarlet Ibis. They are stories that define the emotional limits of your own imagination as you read them, with certain sections or phrases never forgotten, as long as you live.
I read this book in the fifth grade, and I will never forget the line Jess's sister utters when he returned home. When I was younger, I thought it was snide and hateful, but in recent year I've grown to wonder if I read too much into that. Regardless, the fact that the one line I remembered more than any other was NOT in the movie is enough to rate this movie down. The over reach on the fantasy is the rest of the reason why. The acting is very good by the principle two, Josh Hutcherson (Jess) and AnnaSophia Robb (Leslie), and Robert Patrick was a great choice for the gruff and hard father. Can't fault that.
I would say that despite giving the movie two stars, it is worth seeing. But read the book afterwards, NOT before. And if you've already read the book, well, you're going to question a lot of scenes in the movie, much like I did.