World Saver by Neal Goldstein

Eighth-grader Cy Orbick, champion of the World Saver online game, is sent to his aunt’s spiritual retreat to be cured of his gaming habit. Secretly, though, he takes along his laptop and continues playing the World Saver game’s bonus level. He is searching for a “globe,” a tiny replica of an alien world, and if he finds it he’ll earn a summer job at World Saver Studios in L.A. Cy’s globe hunt leads him to Space Ranch, a theme park based on World Saver’s alien realms, and finally into the raw New Mexico desert, where he learns that the game is more real than he imagined. And something tells him that World Saver isn’t quite what its name implies.