It's just something really different, with not many interesting characters (at least in my personal opinion) Though, of course some storylines are quite interesting, and there are interesting characters as well. But if you're expecting another masterpiece like the original series you'll be disappointed. Avatar: The Last Airbender ended back in 2008, but the adventures of Aang and Team Avatar have continued ever since in the pages of Dark Horse comic books. If you like the world, the humour and the whole bending combat, then go for it and watch it. But it does have some good things going for it as well. Overall I was quite disappointed, especially when I compare it to the original series. Every season has it's own little main story, which is a bit sad in my opinion. There is no greater overarching story like in the original series. I especially liked the last season, simply because of Kuvira. But more generally it's about Korra's struggle with her role as an Avatar in a modernized world, who doesn't need benders that much anymore. In the first season it focusses a lot on love and romance between the characters which I really didn't like. It is not as good as the original series in my opinion. It's about the new Avatar Korra, who lives in a modernized world, similar to New York in the 1920's.

Aang is already dead, and everyone you know is already very old and plays almost no active part in the story. Believing in the supremacy of benders and feeling threatened by the new machines that made bending. It is not a 'continuation' of Avatar, it's about 70 years after the events of the original series. There are no movies that continue the story, only a very very bad real life adaption of the cartoon series.

There are futher comic books that continue the story, yes.

Is there any new avatar series