Talvez Killobyte de Piers Anthony?
Not so much a novel as a series of situational puzzles, this stand-alone book by the bestselling author of the Xanth series features two characters who play a computer-generated virtual reality game called Killobyte. Walter Toland, an incapacitated former policeman, and Baal Curran, an angst-ridden, diabetic teenage girl, get to know each other as they enter into a game that calls for them to rescue a princess from a castle. But then they find themselves trapped inside the simulation by a hacker named Phoney Phreak. While the character-bodies they wear in the computer world are in no danger, their real bodies--Baal's weakened by diabetes and Walter's by a bad heart--are very much at risk. Written in Anthony's usual glib style, the novel is unimaginative in the extreme. Watching these paper-thin characters solve uninteresting puzzles is a maddening bore; and gaping holes in the plot, technological inconsistencies and Anthony's apparent ignorance of current methods of treating diabetes combine to make this one of his weakest efforts.