The film was nominated for and won numerous European fantasy film awards, largely for special effects and design, which are striking. "Real" sets are excellently chosen, from the squalid slums to the eerie attics of a grand hotel. Some of the flashback scenes on the other hand, have an other-worldly effect, such as the recounting of the murders done with the alchemist's lighting weapon. The alchemist's lair sports a wonderful "mad lab" where he distills his potions, and Vidoq's prototypical forensic laboratory is good, too. There is a recurring theme of overhead shots of the characters against elaborate floors that make them look like pieces in a complicated game.
Since it is an action-adventure movie, the acting is not wonderful, although the decadent plot is nicely convoluted and kept me guessing.
One caution: the DVD's English soundtrack is dreadful. It is badly dubbed in plain American accent and idiom with voices that clearly do not match the actor's physical types. If I were to watch it again, I would turn on the French voice track and use the English subtitles.
Fun for adults: the disturbing violence and subplot involving child abuse make it not suitable for children.