Well, without having read the 'just call me a god novel', it's hard to say precisely. However, if we look at the title, it gives the impression that the story could be about an individual who is either self - proclaiming to be a god or is being named as such by others. This could lead to a whole host of plotlines, such as how this person deals with the expectations that come with such a title, how they interact with normal mortals, and what kind of world or universe the story is set in that allows for such a concept to exist.
I'm not sure specifically as I haven't read it. But it might be about a character who has god - like qualities or a story where someone is addressed as a god for some special reasons.