What is the author's style in Olive's Ocean by Kevin Henkes?

The story is written in third person from a limited perspective. The story is presented entirely from Martha's point of view. This limitation is not a real problem for the reader because the focus of the story is Martha and her emerging maturity. The reader is given information as Martha gets it or as it occurs to her. For example, Olive has already died when the story begins but there's a chapter that details the reactions of Martha and her best friend, Holly, upon learning of Olive's death. Another important aspect of the perspective is seen when Jimmy Manning kisses Martha. She believes that Jimmy cares about her and the kiss catches her somewhat by surprise. Immediately following the kiss, Martha learns that Jimmy's motivation in kissing Martha had been a bet made between Jimmy and his brothers. Vince also knew about the bet ahead of time. The fact that Jimmy, Vince and the other boys knew about the bet prior to the kiss is not revealed to the reader until after the kiss. This presentation of information is appropriate. The reader feels sympathy for Martha's having fallen into the trap and knowing about the bet ahead of time would have lessened the effect on the reader. The third-person perspective and the limitations are appropriate and acceptable to the story.