Your job is to make your book the best, most compelling version of itself, plausible within its own imagined realm and set of rules. Let others worry about what genre it is (or isn’t). You can self-consciously try to write a horror novel, but this won’t necessarily make you the next Stephen King. You can try to reinterpret a classic legend the way that John Gardner upended the Beowulf story, but that doesn’t mean that scholars will promptly insert your novel into the literary canon. In other words, don’t let genre analysis creep into your writing process. It’s hard enough to be a good writer without obsessing about commercial appeal, so don’t.