Similarities between "Atlantis" and "Avatar"

After watching the film "Avatar", I could not help but compare it with "Atlantis" as they are very similar! Every one seems to overlook the facts that they both;

-include two young men with no experiences out of their own world
- take place in cities thriving with people who are very misunderstood by the modern person
-meet gorgeous women in this different, mysterious culture. They also happen to be the daughters of the prime ruler of the different world
-have cultures who dislike weapons
-have cities that have many glowing things growing everywhere, and wear glowing face masks
-have cities threatening to be destructed
-have small, glowing animals that float around
-fly with large fish and/or birds
-main character rebels against their own people, realizing how precious this new culture is
-men create a group of protagonists who mostly or completely live
-include a thick, muscular man who is at the beginning of the story, a friend. But soon enough, he turns into the cultures antagonist after he is overtaken by greed.
-have similar titles

I know that this movie came out a little bit ago, but better late than never, right? I love James Cameron, but this was just strange. What do you think?