Deep Dive Dungeon a Deaxter Story

What happens when you let a sci-fi astronaut crash into a fantasy world? And his only hope for rescue is an energy source in the core of the planet. Getting there would of course be much easier if the continents didn't fly over and beside each other through the air. Especially if not every continent was a mixture of prison and biosphere. Author comments: This is the first time I've ever written a novel. So I would be grateful for any criticism to improve myself.