"La Cite des Enfants Perdus" or "The City of the Lost Children" is very strange. It was pretty darn good, too.
Plot summary (taken from here):
One, a strong man from a freak show, is on a search for his little brother, Denree, who was kidnapped by the Cyclops' (other beings who look out of one mechanical eye). He meets an orphan girl called Miette and together they find the place where all the children have been taken.
Meanwhile a brain's genetically engineered family are living on an island. The brain's brother, Krank, determined to have dreams, has created a machine where he can steal the children's dreams. In the search of a pleasant dream, he comes across Denree, who is not afraid of Krank.
Miette and One rescue all the children, including Denree (this part happens inside his dream where Miette enters the dream machine as well). The island then blows up and Miette becomes One's little sister.
All clear now? No? Yeah, well, it's french.