You may not believe it but it's bad luck (and bad box-office) to name a film after a fictional character.
You might find the exception of a successful film which is named after a fictional character... but they are the exception.
Jerry Maguire comes to mind. But than that starred Tom Cruise.
Arthur (the original with Dudley Moore) is another. But yes, they are rare.
No, not really true. Here's a few more I can think of that received positive critical reviews, did pretty well at the box office, or both:
* Annie Hall
* Barry Lyndon
* Barton Fink
* Billy Elliot
* Billy Madison
* Cat Ballou
* Donnie Darko
* Edward Scissorhands
* Jack Reacher
* Jackie Brown
* John Carter
* John Wick
* Nancy Drew
* Napoleon Dynamite
* Robin Hood
* Rocky Balboa
* Sherlock Holmes
* Veronica Mars
I'm sure there are plenty more that I haven't thought of, as well. :-)
http://imdb.com/user/ur2019270/ratings