It is basically a 140-minute love fest for Rome, with beautiful cinematography and soundtrack to match. I think one reviewer described it as "Fellini, updated and filtered through Baz Luhrmann" or something like that. It goes from the sublime to the ridiculous (e.g., "performance art" Italian style).
The scene with a giraffe in the Baths of Caracalla and the eerie midnight walk through the Capitoline Museum is reason enough to go see it. (I suspect these sites may get additional tourists now.)
And stay through the credits for a gorgeous rolling shot down the Tiber with all of Rome's bridges.
The film is in Italian with English subtitles.