The special effects were great. I especially liked the infrastructures and bending. The benders did not look like they were having an aneurysm moving one rock. They also showed how Azula is being pushed to the brink by her father. Which was a nice addition to her character arc. But it did made her look soft. Azula was originally cold, calculating and insane. Hopefully they don't take that away from her in season 2.
The reason why I rated this so low is because of the script/dialogues. I find myself cringing every episode and the stiff acting did not help especially the extras. Just when I am starting to get immersed in the story some extra is going to shatter it. The main actors did good especially Zuko, Azula and Sokka. Their delivery was smooth and did the best they could with the script they were given. But Aang was very stiff and monotonous in a lot of scenes and would over act in some. But it got better in the last few episodes.