What is the author's style in Tomorrow, When the War Began by John Marsden?

The story is written in first person from Ellie's perspective. This means the story is somewhat limited but the author gets around this by having Ellie relate the stories of what others endure as those stories were told to her. The reader should be aware that because this is presented from Ellie's perspective, there may be points that are not true to the story. As is always the case, a person's perspective is affected by her background and morals.