First off, Kiki's Delivery Service is a children's movie. It is not meant to be scrutinized to the point of absurdity, but from a general viewpoint this is a well-done movie.
The story is about a young witch named Kiki going through a rite-of-passage, if you will. She departs from her home with her mother's broomstick, a radio, her cat friend Jiji, and a small bag resembling a purse to engage on what is a journey of the spirit, a quest to find herself and develop her magic powers.
The themes Miyazaki presents are well-done, such as female individuality and independence, though sometimes the way Kiki interacts with her world is awkward and out-of-place. For instance, most of her interactions with Tambo are strange. She talks of how she looks forward to having a boyfriend in the first few minutes, then when a nice boy rolls around on a bike trying to be friendly, she shuts him down and flies away. Though it can be explained by her immaturity as a 13-year-old, I thought this scene could have been handled differently.
Beyond that, the narrative is good despite some of the sloppy discrepancies in time. The chronology of the narrative can be a bit awkward sometimes, leaving the audience with questions as to how much time has passed or what time it currently is in the story.
But, the story is there and it is handled correctly, just as all of Miyazaki's movies are.
Studio Ghibli. Enough said.
The music is good, though not memorable.
Kiki's voice is by far one of the most pleasant I have heard in anime. I enjoyed her voice acting all the way through, and her dialogue was well-done. Though I wish Jiji had more lines; his personality, similar to Calcifer from HMC, made me like him as Kiki's support much more.
Kiki's character growth is solid, as she runs her business she gains more independence and confidence in herself, a trait I favor in female protagonists (in actual women as well). Many could not understand why she loses her magic near the end of the movie; it is alluded to through the conversation with her painter friend when Kiki stays at her cabin. Kiki needs to come into her own skin before she can realize the full potential of her abilities, completing the transformation from girl into young lady.
A common complaint from critics is the personalities Miyazaki gives his female leads; they tend to be the same. Kiki is very similar to Sophie and Nausicaa, though I perceive this to be a part of Miyazaki's style. It could be said all of his female protagonists spawn from the same vagina factory, but I find this to be one of Miyazaki's strengths. He wants the women in his movies to be strong, independent, and retain their innocence.
Kiki's Delivery Service is a light-hearted, fun movie people of all ages will enjoy. Some will love it, others will like it, but I have yet to see anyone hate this movie.