I can't fairly review the book without direct comparisons to the Spielberg film that was one of my absolute favourites as a boy of Jim's age. I see now the film was a fine adaption, keeping the chaotic darkness though removing some of the complexity. Of course this means cutting some sections and changing some important details, but it made for a better film. The final third of the book is quite tumultuous (as the situation clearly was) but in a film it would have been a messy side adventure without the big emotional close the book does not have (or need).
The book full of wonderful language and has a great perspective, the innocence of the narrator slowly slipping away as his situation descends into mayhem in wartime Shanghai. One line about the violent 'tango' lesson his mother seems to have had that he sees in the dust of her bedroom hits hard. Later his furious will to adapt and survive while alone shines through. It brings moments of levity too, as when as a now horny 14 year old with a thing for his married woman cabin mate.
There are deeper explorations of identity of nationality - Jim is full of admiration for the brave Japanese, at times thinking of joining their air force, but he is also enchanted by the fast talking and quick thinking Americans - especially Basie, the relationship with him is far better explained in the book. It is only his Britishness he has a hard time accepting, having never been there and having few positive examples in terms of survival or energy outside of the Doctor.