Gotta be really honest here. I didn't care much for the first half of this book. I loved the opening chapters, but as soon as Annie became Ayla, things went downhill. Somewhere around page 200, I was happy I had decided to stick with it. It got much better and by the end of the book, I was happy I had read it. My main issue is this: I have a real problem reading books with unlikable characters if there is nothing else about the book that blows me away. The story or world-building has to make up for it. And at that point in the book, I was feeling very meh about the story. It did get better though.Once Charlie entered the story, my whole outlook on this book changed because I had an awesome character to root for. Charlie was amazing, not only as a love interest, but as an individual character. He was the kind of guy I would have had a crush on in high school, but now that I'm too old for that, I just wanted him to have all of his dreams come true. He was funny, sweet, super-smart, and had a wonderful relationship with his sister that had me wishing I had a sibling while I was growing up.Charlie entered the book and changed Ayla/Annie. Once she met him, she became likable and I began to like this book. And then there was not only Charlie, but his sister as well. She was bad-ass and a girl I would have wanted to be friends with. Her situation was ugly but her personality was sunny and her determination to make the most of life really inspired me. I'm purposely being vague because I don't want to give away anything too important about the story.Things I Didn't Like:~Whiny, unlikable characters, including the parents.~Plot lacked originality, although it was fun.~Stereotyping of the popular kids and jocks as the usual jerks. Can we think of something new already?~The writing was kind of blah. Nothing made it stand out. There was a lot of telling. Where was the imagery?Things I Did Like:~The evolution of the protagonist from a nasty, selfish person to someone I would like to know.~Charlie. Annie's Dad. Charlie's Sister.~The whole idea of the time-travel and the science behind it. I thought it was inventive, even though it was a little hard to believe.Bottom Line:This is a fun read if you are looking for a fluff piece of fiction. It's not all sunshine and roses, but it's not too depressing and it will make you feel good if you don't get annoyed by the things I mentioned. If you stick with it, it gets better. It's not perfect, but what it does it does well. I enjoyed it. I don't know if I would ever re-read it (probably not), but I did have a fun time with this one once it got going.