The unique format - a few pages of text, alternating with a few full-page, wordless pictures that also advance the story - makes this worth reading if you have an interest in experimental storytelling methods and such. Unfortunately, the story itself is not as good as I would like it to be. The characters are fairly one-dimensional, the emotional moments don't ring true, and the plot meanders, relying heavily on coincidence. The source material is interesting on its own, but I often got the sense of the author showing off his research, like when our hero thinks about the Gare Montparnasse train accident for no good narrative reason. It happened "thirty-six years ago," twelve-year-old Hugo recalls, accurately. Come on.
On an odd note, there were at least four or five occasions where an important story moment was precipitated by a character falling down or crashing into something. This didn't seem like an intentional motif, just a lazy way to move the plot along.
I'm still glad I read this, again, for the interesting form, and because I learned about Georges Melies. But it doesn't live up to its potential.