I think when this movie was first announced there was uproar of people who didn't want the beloved Dr. Seuss classic soiled by a Hollywood watered down version. Now, I will say that the book is better, but there are some things about it that work.
Now arguably, the film does go for a more light-hearted tone than the book which was very heavy handed and dark, as it should be since it is supposed to be a cautionary tale about how mankind shouldn't do nothing, and if they do, the problem isn't going to go away it's only going to get worse. Because of that, the novel ends on a feeling of caution but light hope. The movie, on the other hand, actually semi-resolves the issue and ends on a feeling of strong hopefulness and satisfaction. Which ending works better? Well, I personally think the book has a better ending, but for my money, the movie handles the happy ending well, not showing too much, and still leaving the viewers with a feeling of responsibility.
But with that said, I must bring up the film's fatal flaw, and the main reason why this film isn't as good as it could've been. The film is just too preachy. We get it, trees are awesome. Also, I have to raise some complaint that the film seems to have Anti-Capitalist leanings, stating that business is bad. I think the film sadly doesn't find a perfect balance between corrupt capitalism and the appreciation of nature. There is very little subtlety in this film. Okay, the book wasn't exactly subtle either, but it was more subtle than this.
I will say that the film does at least seem to be self-aware that it is preachy and tries to have fun with it. The scene where the first tree is chopped, all the creatures put rocks around the stump like it's a grave. I'm not sure if it was done seriously or not, but I will say that I laughed.
The film is actually quite funny and I laughed a lot during the film. Maybe that's not what the story quite needs, but heck, it's a lighthearted family comedy, and I think its funny enough.
I will also say that the computer animation is just stellar. It looks jaw-droppingly unbelievable, and even without the 3-D it feels like you're transported into another world. The trees look so soft you can practically feel them. It creates a great atmosphere and it's phenomenal.
The one thing that I think the film actually improved from the book is the portrayal of the Once-ler. In the book, he is faceless, and represents stubborn businessmen who refuse to compromise in order for the environment to be cleaner. So it makes sense that he is faceless. In the film, however, the Once-ler is a young naive entrepreneur who is a nice guy with good intentions, but when he becomes successful, his success goes to his head, and the people he surrounds himself with try to get him to renegade on his promises and his circumstances force him to make a difficult decision. It makes the character more tragic and not only strengthens the theme of human's responsibility for ecological preservation, but also offers a cautionary tale about the downside and dangers of capitalism, and the tragedy of a man who realizes his mistakes too late. It's a fascinating character and is an improvement over the book's portrayal (the books isn't bad, I just think the movies way of showing the character is more interesting).
It's bright, it's colorful, it's funny, it's a decent, nice trip. Some people will strongly object to the somewhat anti-corporate message (funny seeing how many tie-ins I saw for The Lorax), and the complete lack of subtlety (seriously, some subtlety would've been nice, guys), but I think the film is charming and funny enough, and the film is saying that we need to take care of the environment, not necessarily a bad thing. But, man this film had potential to be fantastic, especially with such a great character in the form of The Once-ler.