This book may deal with some of the biggest, hardest questions in, well, the known universe, but Rosoff makes it pretty easy on us. Check it out: "The hill is steep and he begins to run. She stops when he says her name. He leans on her shoulder for a second to get his breath back" (48.4). She's usually a bit friendlier with commas, but you get the idea. Simple language for big ideas is a good idea because it helps us not be confused by the million and one things that are going on.
Then on top of the simple language, Rosoff paints pictures for us that are so descriptive that we have no problem at all playing the scenes out in our heads like movies. This scene with Mr. B on Earth is a good example:
As he paddled steadily through the outskirts of the city, the artificial light slipped away and, with it, the trapped-fly buzz of humanity. He stopped for a moment, drifting in silence through the drizzle. The moon had just begun to rise, a great orange disc, majestic and strange. Little boats manned by dark silhouettes bobbed in the floodwater; soft voices came to him across the land that was no longer land. Mr. B sat motionless, mesmerized by the tiny percussion of raindrops, plinketytink, like plucked strings. A path of silver moonbeam crossed the floodwater toward him and he slipped into it, shifting his paddle so that he drifted along its length. He felt he might follow it forever. (34.16)
Well played, Rosoff. Not only is this really beautiful writing, but it's so descriptive that we can just hear the "plinkeytink" of the raindrops and feel the soft calm of Mr. B floating on the water. Gorgeous, sensory details like this ground the book, so what seems totally crazy—a horny teenage God—ends up feeling, well, kind of real.