Terrible film, and an even worst adaptation. I am sure everyone has heard the criticism and issues with this movie, but if you haven't already I reccomend you watch a YouTube video on everything Shyamalan did wrong with this movie.
Spoiler for the TV show coming by the way.
With that being said, there is one specific mistake in this film I would like to point out that is catastrophic to the ENTIRE plot of the TV show and what would be the later movies. If anyone here has watched the show, you should know that Prince Zuko's whole character arc is built off the premise that he is conflicted between good and evil. We later find out that the reason for that is because he is the decendent of the previous Avatar on his mom's side of the family, and decendent of the previous Fire Lord from his dad's side. Both are polar opposites, so it is up to him to decide which family side or path he follows. The Avatar path is obviously the good one, and vice versa.
Here in the movie, one line completely craps on this idea and makes it impossible for things to actually make sense. It is when Aang (or Ong from how they say it in the film) is told that the "Avatar can't have a family." Let that sink in for a moment. The Avatar can't have a family. So with that being the case, how TF does Zuko even exist? It literally make no sense and I'm convinced Shyamalan doesn't even understand Zuko's character. If the Avatar can't have a family, Zuko, pretty much the main antagonist of this movie, would not be alive. How was he even born? Why would he save Aang as the Blue Spirit if he supposedly was not even tied to the Avatar biologically? He wouldn't even have this eternal conflict! It's crazy how a mistake like this even went unnotice