All I can possibly say is please do not judge the show on this clusterf*** of a movie. The show genius-sly tied together both playful fun with dark and depressing subject matter.
For example the main protagonist Aang (pronounced aang not uung) is a troubled child who represses his guilt and sadness with excessive amounts of humor and levity whilst one of the main Antagonists Zuko deals with a similar guilt a completely different way via anger and determination.
This show has beautiful writing, characters, story, action, and scenery with complex moral dilemas that leave you wondering what you would do in their situation.
All in all the original is a 20/10 whist this "movie" is worth 0.2/10