Miyazaki has been doing his mojo since the 70s and it's only been recently that his movies have made it American shores via Disney and fans fawning over his great talent. Ponyo is no exception. Although some of his other movies have been a bit more accessible to US audiences, some may find this one a bit on the fence being sort-of "Japanese" in its presentation. For the same reason Pom Poko is VERY "Japanese" and doesn't make much sense to US audiences, so too are *some* elements of Ponyo. This should not detract you from watching this fun film of growth, hope, and friendship.
What does come across well is Miyazaki's very elaborate and magical animation and story that has elements of wonder and fantasy. That coupled with his characteristic use of character development and often using girls and women as main characters. He steps out of his zone a bit with Ponyo as the main character is a little boy who lives in a small village by the sea with his mom while his dad is away at work on the high seas. Although not lonely, Sosuke is just like any other curious boy who likes adventure and allure of the sea. Similar to Spirited Away, we see the different worlds of the humans and the sea creatures and I feel that Miyazaki may be trying to draw the viewers attention to the vast and undiscovered nature of things that live beneath the sea and our acceptance of them and thing that are different.
I managed to watch the subtitled version of this last year and was pleased by the story and plot. Miyazaki has claimed that "this is my last movie" for many years but shortly after Spirited Away, he gave us Howl's Moving Castle. Ponyo is certainly proof that Miyazaki has not hung up his spurs and continues to delight, innovate, and pioneer the most creative animated movies of all time. Watch Ponyo with an open mind and a tip of the hat to childhood fantasy and imagination and you'll be transported back to when catching Fireflies and secret hiding places were more important than boring grown-up stuff and eating your vegetables.