I personally found it beyond belief that Elvis would have been taken from his habitat and willingly watched video games, but it's believable and goofy enough that tweens will love it. Slacker and Level 13 push the boundaries of believability while remaining a realistic fiction novel. Other novels involving video games tend more toward fantasy such as Markell's The Game Masters of Garden Place (which is more RPGs), Schreiber's Game Over, Pete Watson, Ali-A's Game On! the Graphic Novel, Brown' s Josh Baxter Levels Up, and my favorite, Anderson's Insert Coin to Continue.
One of my copies of Slacker walked away; I suspect it was stolen by a student who couldn't bear to part with it. I'm reordering a copy so I have two of the first book. I wouldn't mind seeing another volume or two of Cam's adventures.