Plot: Hey Arnold! Follows about a boy that always hangs out with his friends, make fun as soon as possible, and always goes to school. A boy with a good manner. And this cartoon also follows about a girl named Helga who has a very obsessive crush on Arnold. Quite good, because it's two plot lines are unusual when it comes to cartoons.
Characters: Those characters built a foundation in detail and attitudes, an inspiration. They're special. Also, voice acting fits in the whole show.
Humor: It had some good comical humor that are sometimes satiric, and there's some sexual innuendos too.
Art: The art is great, when you are looking for old-styled cartoons.
Overall: 9.5 Started in the right time, ended in the right time.