With any movie adaptation of a popular story, there are criticisms. One fairly thorough list of differences between the anime and manga is here. Here are some of the main points:
* In the film, Goku is a semi-normal high school student, rather than a childish monkey-boy with a tail who lives in the woods. However, even in the anime and manga, Goku does eventually grow up from a three-foot-tall Peanuts character into a normal-sized, perhaps Chatwin-sized adult.
* Piccolo's skin isn't a very bright green, and he doesn't seem to have antennae
* Master Roshi, who in the manga is a dirty old man who asks to look at Bulma's panties in return for a Dragon Ball, doesn't commit any acts of sexual harassment
* a bunch of characters have been removed, including Kuririn (Goku's fellow student under Master Roshi), the talking animals Pu'ar and Oolong, and Master Roshi's pet turtle
* plenty of plots and subplots have been removed, leaving the movie as kind of a mixture of Dragon Ball volumes 1-2 (the introduction of Goku and Bulma) and 13-16 (the introduction of Piccolo, and the big fight).
There's plenty more. A more serious complaint, however, is that "the script is an absolute, unmitigated disaster," to quote Zach Berlatsky of anime news network. What does the creator, Akira Toriyama himself, think about the Dragonball adaptation? Here's a translation of his words in a text announcement preceding a February 2009 promotional video:
"As the original creator, I had a feeling of "Huh?" upon seeing the screenplay and the character designs, but the director, all the actors, the staff, and the rest are nothing but "ultra" high-caliber people. Maybe the right way for me and all the fans to appreciate it is as a New Dragonball of a different dimension. Perhaps, this might become a great masterpiece of power! Hey, I look forward to it!!"
Toriyama is more charitable to Hollywood than Alan Moore-but then again, Toriyama, like most manga artists, has always had no illusions about producing mass entertainment. (Incidentally, it's worth mentioning that Dragonball: Evolution is not the first Dragon Ball film; that honor goes to 1989's Dragon Ball: The Magic Begins, an unlicensed Chinese live-action adaptation.)
The best thing going for Dragonball: Evolution is that, beneath all the spiky hair and shouting, Akira Toriyama's Dragon Ball is a good story. (Particularly if you're a 14-year-old boy.) The fights and cliffhangers are exciting, the villains are reprehensible and the heroes are noble (and sometimes the villains are noble too, deep down), and the mixture of sci-fi, fantasy and comedy is entertaining and imaginative.
But there are other elements of Dragon Ball which may be difficult to make the transition to live action. One of these is the quirky, simple art style which gives Toriyama's work so much of its appeal. Toriyama's stories may be intense by the standards of American children's animation, but the appeal of his art is the cartooniness, which, when Dragon Ball started in the '80s, stood out among more square-jawed macho manga like City Hunter and Fist of the North Star. (Today, on the other hand, the influence of Dragon Ball has made the big-eyed, spiky-haired angular look the default manga style.) Putting simple, cartoony characters in dramatic situations is one of the trademark elements of manga and anime, and a more interesting way to adapt Dragon Ball might have been with film-quality animation or CGI, like the upcoming Astro Boy live-action movie. Although Keanu Reeves may not look entirely like Spike Spiegel in Cowboy Bebop, no real human being can look quite like a Toriyama character.
To use another example, Akira is set in a recognizably real urban sci-fi environment, but Dragon Ball is set in a primary-colored, fairytale world. The Wachowski Bros.' Speed Racer tried the "live-action cartoon" approach, with mixed success, but will Dragonball: Evolution go the grim-and-gritty route and turn out like the live-action Super Mario Bros.? Manga and anime fans cringe at the word "cartoon," but it's a good word to describe Toriyama's creations: a world which combines aliens and magic dragons, comedy and drama, absurdity and sincerity, a world of sweat and blood and winking unrealism.