It seems that Luc Besson consciously sets out to explore a different genre with each new movie. This is a film that would always be in danger of being unwatchable if directed with less skill.
Given the constraints it sets upon itself (almost entirely silent & in black and white), the film is quite gripping (particularly after the first fifteen minutes) and very suggestive.
Certain elements of the plot are a little twee, however it does develop its vision in a meaningful manner, with three contrasting main roles. The absence of language helps raise questions on the relative virtues of each of the lead characters, and the dominant theme of the lead character's sexual frustration helps to afford the film momentum.
A daring film, that is far better than it might have been.