Story: A bit confusing if you don't pay attention closely to minor details. When you do, you realize how amazing the story is. I found a lot of plot twist, which made the story more enjoyable and thrilling to watch.
Art: For it being created in 2006, the animations were pretty well done, especially the fight scenes.
Sound:-
Character: The characters are honestly so undpreticable. Most, like the protagonist, have secrets that are yet to be unveiled and completely different auras in some situations. This is why I am so intrigued.:)
Overall: if you don't mind some long battles and long talks about war strategy, then you'll definetly enjoy Code Geass:)