I found this virtually unwatchable. John Malkovitch had a horrific French/Belgian/whatever accent, which I found incredibly distracting. Living in Canada's capital, I hear French-inflected English every day, and this sounded like nothing I've ever heard. He didn't try for a French accent for his brilliant performance in Dangerous Liaisons, so why do it here?
His mannerisms were also eccentric and delayed — kind of like sound that's out of sync — making his reactions confusing. Was he sympathetic, sad, angry, happy, worried, thinking? Hard to say most of the time.
Also, what the heck on the back story? Whether or not you know the original story, the whole priest-became-a-detective thing was just plain silly, and milked incessantly in flashbacks. When the aspring-to-be-melodramatic "big reveal" finally came, it was definitely a "meh."
The pacing was weird, the production looked unnecessarily cheap and miserable, and the colour palette made everything look like it was filmed in the Soviet Union in the 1950s. To make matters worse in a whodunit, which is necessarily character-driven, the characters were almost all one-note, and some of the plot and acting touches were so weird and outré that I might as well have been watching something by Terry Pratchett, rather than Agatha Christie.
Save your three hours, because life's too precious to waste on something like this. I have no clue why I stuck it out, other than a vain hope that it would get better at some point. Sadly, it didn't.