When one is attempting to consider if something adheres to the definition of 'metafiction' there are certain criteria to look for.
First, is there a degree of self-reflexivity? In other words, does the author break the 'plausible impossible' to speak directly to the audience and draw attention to the writing process itself, or to himself?
Secondly, there is authorial intrusion in that the author purposely involves himself with the characters, questions how narrative assumptions force one to draw conclusions and that reality, is in effect, in the eye of the beholder.