I find it difficult to write anything about this odd gem. Don't expect a hard logical development like in an Agatha Christie book adaptation. From the start, in the character's description, you know you are in front of a farcical/ burlesque whodunit.
Like in Resnais'"Les herbes folles", "On connaît la chanson" and "Smoking/No Smoking" (all starring the perfect actress, Sabine Azema, the last two also with Pierre Arditi as on this film) this films relates more to the brain than to "our hearts", to simplify it.
Some will call this kind of film "typically French", I really don't think so; in any case I hope not :).
The technical aspects are of course perfect, images in particular.
Directed by the brother of actor Denis Podalydès, who also has a family relation playing himself as a child, this film feels like those fanzines that make roar of laughter some selected club of "insiders", and leave the rest wondering what's it all about. Don't get me wrong, I liked having watched this film, but I understand it's not for everybody.
My favourite scene is when Rouletabille is trying to hide himself, but ends up making noises in the most unbelievable of ways, like a "mad machine".
Enjoy.