Time Out says
A sickly boy develops magical powers in this French cartoon
This imaginative hand-drawn cartoon from the French directors of ‘A Cat in Paris’ suffers from an overly busy plot and a general sense of familiarity. When young cancer sufferer Leo is taken back to hospital for chemo, he discovers an amazing gift: he can leave his body and float around the city, unseen but alert. This comes in handy when he assists wounded cop Alex in tracking down a mysterious gangster, The Face, who is holding the people of New York to ransom. ‘Phantom Boy’ is frequently beautiful to look at, but the cops-and-robbers angle feels tired and the characters are thinly sketched.