Like Le Million, Under the Roofs of Paris is what is generally characterized as a "light confection." These are the kind of crowd-pleasing films that evolved into the screwball comedies of the 30s and 40s and subsequently became the romantic comedies of today. Unlike their modern counterparts, however, Clair's films are innovative and technically playful, especially in their use of sound to elevate set pieces or gags.
The plot of the film is extremely simple, focusing on a love triangle in the streets of Paris. At this early stage in the medium's history, this was enough to make the movie novel, especially the setting, which Clair would also depict in Le Million. These days, it could use a few more twists to make it interesting. Still, the film is worthwhile because of Clair's ability to entertain in even the smallest moments, like when he uses sound to turn a shoe into an alarm clock. Under the Roofs of Paris is more of a historical curiosity than Le Million, but it's a pleasurable one thanks to Clair's notable talent.