Shyamalan takes a stunningly sophisticated cartoon and reduces it to one of the most insultingly dumb films I've seen in years. From the script to the visuals, the directing, the acting, there is absolutely nothing that did well, either as an adaptation or as a film in its own right.
Characters who were once powerful and spitfire (Katara) or entertainingly sarcastic (Sokka) are now bland and exist solely for the purpose of exposition. In fact, the entire film comes off as exposition, far too much of the dialog serving as "by the way" explanations, never allowing the plot or characters to really take form. The scenes seem episodic and unconnected, and the film never comfortably establishes its universe, always retreading with an "as you know" or "aren't you that guy who..." to establish (often unnecessary) continuity.
The style, too, is disappointing, capturing none of the magic of the series. Most noticeable was the "bending"--while the series took its martial arts seriously, carefully aligning real-world arts with elements and making the benders' movements coincide with those of their elements, the film gives us characters flailing in generic martial arts forms for a few minutes, only to effect one splash, boulder, or blast of fire. In the series, every movement had a meaning; in the film, only about one in ten does.
Many fans of the series who were angry at the "whitewashing" of the cast hoped that it had at least resulted in the best actors for the parts. However, the acting was at best uninspired, and at worst painfully awkward, though part of this can be attributed to a truly atrocious script. Dialog is stilted and unnatural, certain phrases are repeated needlessly throughout ("great library," anyone?), and in all the only chance the script stands of being remembered is through memetic appreciation of its unintentional, awkward hilarity.
Not even the collective will of a devoted fanbase wanting so much for this film to be good could make it even remotely watchable.
