So I have this story called Encased in White Clockwork and I need some advice around how to market its genre.

The story seems to be set in a fantasy world but a twist late on shows it to be in fact a sci-fi instead. I do lay hints in the story so it doesn’t seem to come out of left field. Yet, I am wondering if in terms of the blurb and how I market which genre the story is in if I should lay out all my cards upfront, so people know what they are getting into or if I should keep it a twist?

From a plot point of view, knowing that the world is sci-fi, wouldn’t spoil the story, not if I did it right, but in my mind at least it would be better to keep it a twist. What do people think?