Things the Sherlock Holmes sequel did right, in no particular order:

Less action-for-the-sake-of-action feeling to it than the original. Sequences that showed the inner workings of Holmes’ mind; not so much how he is eight steps ahead of anyone else, but at least the demonstrable fact that he is. (Though maybe the first one did too? I can’t recall.) Sufficient use of Doyle’s canon that I was able to anticipate certain events and recognize others. Robert Downey Jr. Stephen Fry. Still excellent Holmes/Watson chemistry.

Things the movie did wrong, in no particular order:

Y’know, I got nothing. It was light and fun and better than its progenitor, and what more do you really need? Oh, right, if you care, blah blah Moriarty, anarchists, gypsies, unstable Europe, Reichenbach. That should pretty well ought to cover it, except to promise that you will laugh.