I selected the following trailer, because it introduces a “first fantasy novel.” Let’s take a look:
My first reaction to this trailer was annoyance. Maybe it’s just that I’m tired, but the flashing “lights” created by pictures blinking in and out hurt my head. It also made me feel a little dizzy and a little nauseated. This was quite a distraction from the actual material. On the one hand, I suppose it could be described as “interesting visual effects,” but I’m not sure what effect it adds to the material—other than my own discomfort.
Taking a step back from this technical detail, I think back to the material shown and am left with an outline of sorts. The details don’t particularly stand out in my mind. A fantasy book with a visit from aliens is questionable. Starting out as a rancher—living a quiet life—seems interesting. I wonder what that lifestyle might bring to his efforts. There seems to be a lot of world-hopping for a fantasy novel, too. Mages are after Earth. That’s all I remember.
As a writer, I see potential in these events. But events alone don’t make for an interesting story. What makes this rancher do whatever it is he’s supposed to be doing? What drives the narrative? Why three worlds? What does it matter? These are the things that would capture me.
The outline of your story may or may not be motivating for readers. Regardless of whether it is, it’s not enough. What is the heart of your story? If you’re going to spend nearly two minutes and the viewer comes away without knowing the answer, then you’ve wasted your time—and theirs. The latter is much worse than the former.