I'll be kind and open my review with the elements I feel this movie did right. The visuals of the movie were impressive, from the sweeping landscapes to the set design to the bending visual effects. The music, while more generic than what we heard in the show, was intense and moving. Certain characters and scenes were done well. I thought Iroh, in most cases, was easily recognizable as the wise, good-natured old aesthete from the show. The rescue by the Blue Spirit was well done, for the most part. And Azula, for all that she appears for 4 seconds, struck me as being properly bat-crazy-evil.
Some of the changes the movie made were acceptable, to be put down to Pragmatic Adaptation
or even (minor) Adaptation Distillation
. The decision to increase the time frame of the story to 4 years will allow the romance subplot between Aang and Katara to develop at a more natural rate (and to culminate at a more natural age, something that bothered me slightly in the cartoon series). The requirement of non-Master-level Firebenders to have a source of flame didn't bother me, as it made Firebending line up more properly with the other bending disciplines. The plot compression is unavoidable, in order to present a 20-episode series in 2 hours.
The above said, the movie sadly failed to live up to the sum of its parts. The dialogue was frankly disappointing (I haven't cringed this much since the Star Wars prequel romance subplots). It seemed that everything that made the main characters unique was washed away, leaving a bland patina of vague good-guy-iness. There were far too many plot holes and Fridge Logic
moments that didn't even need a trip to the fridge later. Many of these have been touched upon by previous reviews - the decision to hold Earthbenders on the ground, the reluctance of said Earthbenders to rockalanche the Fire Nation soldiers into dirt, and Iroh's "I'm going to call fire and do... nothing" moment come most readily to mind. Honestly, it was hard to see what Shymalan was going for in this movie. The pace was too slow and stretched-out to be a good action film, there wasn't nearly enough humor for a comedy, and there was too little characterization for any sort of drama. In the end, the film just fell flat.