This story reminded me a bit of the film 'Chicken Run'. It is about a penguin who wants to fly, but cannot naturally. His friend (a human boy) tries to help him, but in the end, the penguin takes it upon himself to join a circus act and be propelled out of a cannon! The penguin regrets his decision when he leaves his friend and has to face his flight on his own. Friendship is a key theme throughout the story - will the boy come to his rescue?
I think this is a great picturebook, where children have to read the pictures as well as the text in order to fully understand the story. For example, the text purely says that the penguin kept on trying to fly, but the illustrations show his methods (e.g. jumping off furniture, tying a balloon to himself). There are very amusing parts in this story, again shown through the illustrations. For example, when the boy has lost his penguin friend but then thinks he has found him (he is in a penguin enclosure at a zoo with 6 penguins). Moreover, colour is used well in this story to portray emotions - the illustrations are very light until the penguin and friend loose eachother, when the illustrations become very dark. There are lots of opportunities for book talk here.
I would definitely use this with KS1, and even lower KS2. Links could be made with the science of flying, animal adaptations, the history of people in space and the circus.