Sailor Moon is admittedly for a younger audience and targeted at a mostly female audience. On the surface it seems to be a simple fantasy story about several teenagers with special powers striving to save the world from evil forces.
The story itself deals with the struggle of friendships, morality, love and fate. I would argue that the action is only mediocre, and the action and fighting between good and evil is only a small part of the Sailor Moon saga.
Takeuchi Naoko, the original author of Sailor Moon, manages to incorporate a deeper saga into the storyline. It also brings into views on sexuality which are edited within the American dubbed versionThe soap opera-like quality of Sailor Moon helps to grasp at the appeal of an older audience as well.