The IMDB categorizes I Care a Lot as a comedy crime thriller, which is accurate enough ... I laughed at times, crimes take place, there are thrilling moments. It's not even a jumble for the first hour or so. Rosamund Pike does a lot to make the film cohere. She's great as Marla Grayson, the Bad Guy, and she manages to do some very over-the-top things while keeping what passes for calm. She's fun to watch ... that's where the comedy comes in, I guess. Peter Dinklage (Roman Lunyov) is a different kind of Bad Guy, and his acting isn't quite the same as Pike's ... he lets us see the effort his character puts into appearing calm, and also lets us see when his anger gets the best of him.
J Blakeson, who also wrote I Care a Lot, goes full bore into giving us what amounts to an evil, calculating person. Some people have found anti-capitalism undertones, and even some feminist empowerment. But the movie mostly feels like Blakeson wanted to give us a good time, which is how you end up with a comedy crime thriller.
Still, at some point, Blakeson has to address the central problem of the movie: the main character is essentially despicable, and the audience will only go so far before we realize Marla isn't a hero or an anti-hero, but a Bad Guy. When you reach that point, you have no one to root for. Honestly, I like movies filled with people who can't be salvaged, but Blakeson wants to give us a reason to turn to Marla's side. He solves this problem by bringing in Lunyov, who is an even worse person than Marla. Marla doesn't suddenly become good ... in fact, it's refreshing that she never comes around, never leaves the dark side. But when the two stars share scenes together, Marla is the one we gravitate towards, rather like voting for the least bad candidate in an unsatisfying election.
The way the two antagonists go at each other keeps I Care a Lot moving until the final scene, and you'll find it enjoyable as long as you leave your moral qualms in the theater lobby. The ending, though, feels like it was tacked on by censors from the era of the Code.
I Care a Lot is as despicable as its characters, and that's not necessarily a bad thing. But I felt it was less than the sum of its parts.