Terrible.
All the "professional reviews" I've read refer to this movie as a dark comedy. ABC even says it "shockingly funny". I dare those reviewers to point to a scene that is funny. I couldn't even muster a smile, let alone a laugh for the entire movie.
This movie is very dark, and there is nothing wrong with that. There are dozens of great movies depicting evil, malicious and brutal sociopaths.
The problem with I Care A Lot is that every single character in the movie is morally corrupt. Everyone is in on it, wittingly or not.
There is no hero. Not even close. No one to root for, no possibility for resolution. I'm not asking for a happy ending, but at least throw in a sliver of hope or a speck of light in the darkness!
And what's even worse is the ending when you realize that there isn't even real justice.
Don't waste your time.