The Giver started out as a very drawing in dystopian story with elements of fantasy aimed at young adults. Lowry described a perfect society where people don't have to worry about anything, especially about choices: your home, the clothes you wear, your profession, your parents, your children, your spouse - everything is selected by a committee of Elders who know what's best for you. Individuality is a banished notion and nothing to be proud of, everything is grey and pretty much identical, as the community praises the notion of Sameness. However, people know nothing about real feelings, pleasure, pain, love, loss - those memories were taken away from them, so that they could live safely and without worry. People who disobey are 'released' from the community. So yes, the setting is very intriguing and satisfying. 
 About the main character: 
 (view spoiler)[ 
 Jonas, the protagonist, age 12, is assigned an extremely rare profession - The Receiver of Memories and gets trained by the current Receiver, which eventually becomes The Giver. He experiences all possible memories and feelings, finds out what real family is, experiences warfare, learns all the colors and sensations of life. After that he can no longer perceive his community the way he did before. He hates it and realises that people should have feelings and memories too. (hide spoiler)] 
 So, the protagonist is also believable and likeable and one can see growth within him as a person. 
 Having said that, I'm only giving this book 3 stars because it ended so abruptly. The tension was building and I didn't want the book to end, but at the same time could not wait to see what's going to happen in the end; however, Lowry spoilt the ending, ruined it big time. By the end of the book, the reader has no idea what'll happen to Jonas, what's going on back at his community, how did things turn out for The Giver. NO answers whatsoever are given. Thus, after finishing the book I had only one frustrated question in mind: that's it?! I even re-read the last two chapters, hoping I'd understand more, but there was nothing. 
 The message of the story is clear (seeing the reactions of the main character "before" and "after" he'd become The Receiver), but I can't give a higher rating to a story with no ending.