Well it all kind of blurs and depends on what you are looking at - I will admit... and technically wouldn't ANY game be a Role Playing Game - as your taking the role on of whatever it is you are controlling, interacting with etc.
And I love Faxanadu.
But really mostly "RPG" means to many back into its origins with FF, DQ and Pen and Paper games such as D&D - so usually that means things that are stat based, character sheets - equipment - story driven interaction and not so much on the "action" side of control/game interaction methodology but a more "command" based system where your stats make up your "actions effectiveness" not your control of the character in an action battle situation etc.
While technology has certainly merged many of the typical old types of games into one, such as adventure, rpg, action etc.