I don’t even have anything to compare this book with. I've never read anything that was both fantasy and animal fiction. "The Hill Dwellers" is a fairly large-scale novel about the life of rabbits.
The plot is this: several rabbits, sensing something is wrong, leave their town in search of a better life. They go nowhere and move at random. They are looking for a place where they could feel safe, but this is a very difficult task: everywhere there are either people, or predators, or other rabbits. The main characters are constantly in danger and even lose some of their comrades, but when they finally find the promised land, they discover that they cannot build a new colony, because they do not have rabbits. A new challenge is to get friends in life, otherwise what is all this for? “When would it not be for Helen, that Troy is yours alone, Achaean men...”
Rabbits can talk, have high intelligence, experience complex feelings, and build a comprehensive social structure. They have folklore and something like a religion. Each rabbit town has its own political regime, from democracy to totalitarianism. Rabbits easily go to war against someone else's rabbit settlement and just as easily form alliances with other animals. But this is not a fairy tale about animals in the forest and not a saga about the life of fairy folk. Heroes do not walk on two legs, do not wear clothes, do not make tools and do not furnish their holes. Rabbits live like rabbits; using this book you can study their habits and way of life.
This story, written 50 years ago, has become a classic of English literature, and images from it are widely used in later works of fiction. So, in order to improve your education, you need to read, but I find it difficult to name the target audience. There are tough episodes with deaths, injuries and suffering - not suitable for the impressionable. Probably for morally stable teenagers who love fantasy, adventure and animals.