Guy Ritches Sherlock Holmes is not your fathers Sherlock Holmes. This Holmes is crazy half drunken and charasmatic. Played by Robert Downey Jr as a bit of crazed artist than a calm logically driven dry dectective. Downeys ferocity is matched by the normal Guy Ritche troupes such as a playing with the timeline. inner monologues, and a general manic style.
This time Holmes faces the mysterious and possibly magical Lord Blackwood not the normal Professor Moriarty or hound from hell. The super natural elements of this story contrasting with the normal Holmes science and logic adds for a bit of intrigue. Also Holmes and Watson are not the normal chummy bunch. They are instead in transition and are like a married couple in a the process of divorce.
This works in a great deal due to the chemistry between Judd Law and Downey Jr. The acting overall is good to serviceable. Downey carries the bulk of the film with his normal Robery Downeyness that is a mixture of smarmy asshole and generally likable. This actually makes him a rather good fit for the modern idea of Sherlock Holmes. Judd Law is the unsung hero of this film being able to convey the emotional points of the movie and give someone to like in a abused spouse sort of way. Mark Strong was good as the snarling Lord Blackwood. He was menacing and mysterious which is exactly what was needed. The weak point is Rachel McAdams she is left to play the simple girl who got away and love interest. Its rather boring compared to everyone else.
The world of a turn of the century London is rather drab and grey which fits the time. This grayness also helps make the smattering of color pop even more like in Sin City. London like this Holmes is dirty and crazy.
The only gripes with this movie is the middle acts are a bit aimless. The middle part of any good mystery is finding clues that implicate things and people. The middle bits of this movie just are episodic and confusing to just what went on.