With each shapes outing Klassen outdoes himself on doing much with little; in this case, the succession of spreads that go from gloomy to inky black, with only eyes to represent the characters, sets a high-water mark of minimalism that will be hard to beat but that works effortlessly and comedically within context. The book concludes by inviting the audience to join the shape friends in imagining what the being in the cave could be. That suggestion, issued with a light touch, moves deftly on from the story’s summation without breaking the mood, so even kids resistant to more didactic entreaties may be enticed to join the characters as they wonder.
—Bulletin of the Center for Children's Books (starred review)
Square and Triangle have had their turns. Now, in the final volume of Barnett and Klassen’s shapes trilogy, Circle’s the hero...Circle’s story offers a moment of genuine fright; watching Circle consider other possibilities reminds readers that calm analysis can master fear.
—Publishers Weekly
Illustrator Klassen's watercolor, graphite, and digitally created illustrations are evocative in their muted palette and spare presentation...the implied message of the story is a vital one in this xenophobic age and its subtle delivery and imagery encourage further exploration.
—Kirkus Reviews
In typical Barnett-Klassen style, humor and light philosophical musings mingle to form a story that will entertain children and adults alike. Because much of the story takes place in darkness, readers are called upon to use their imaginations, making this oddball friendship tale an off-kilter treat...If you don't order extra copies of this dynamic duo's latest, their fans will get bent out of shape.
—Booklist
...the message is highly entertaining in its delivery, and Klassen’s understated work with light (and the absence of it), shadow, and texture carries the story full…circle.
—The Horn Book
Klassen paints a wonderfully mysterious backdrop of waterfall, concealing a dark cave behind it. His simple shapes with their stick legs and expressive eyes are full of personality. Barnett's subtle, witty text pokes gentle fun at the friends' foibles and fears in a way sure to appeal to children in the target age group.
—Buffalo News
Like Square and Triangle, Circle teaches shapes while challenging kids to think, in this case, about what they know and don't know.
—Northwest Arkansas Democrat Gazette
Offer[s] young readers plenty of opportunity to read their own ideas into the story, flex their imagination, and explore their own fear of the unfamiliar.
—New York Journal of Books
An elegant picturebook in which simple shapes and succinct story express big ideas. Here a game of hide-and-seek makes us consider, for starters, fear of strangers, the power of the imagination, being brave and standing by friends.
—The Sunday Times
