Video Game Violence
Bowser. Ganondorf. Senator Joe Lieberman. What do they all have in common? Besides being magical shape-shifters, all three men are classic video game villains. Bowser battles Mario. Ganondorf attempts to slay Link. And Joe Lieberman fought against the entire video game industry.
Lieberman headed a high-powered hearing on video game violence in the early 90s, which eventually led to the video game rating system we have today. He believed that video game violence equated to or sparked real violence (source).
It's difficult to tell where Sherrilyn Kenyon falls on this argument. In one corner, we have Nick, who loves video games. When in the hospital, he wants a Nintendo to pass the time. "I'd kill for Nintendo" (3.32), he tells Nekoda. Don't say that too loud, Nick, or Lieberman will come after you.
Nekoda brings Nick her "Nintendo," which is really vague. Considering this book might be set in the mid-90s, it could actually be a black-and-pea-soup-green original Game Boy she lends Nick. If so, we hope she gives him a sack of AAs to keep the juice flowing. As Nick says, "Systems were personal" (3.60), and he takes it as a compliment and a signal of trust that Nekoda lends her system to him.
So that's one positive representation of video games. But in the other corner, we have Madaug. who designs a video game that literally makes people violent. While playing it, Nick thinks, "With every kill he felt more powerful. More invincible" (17.151-17.152). This is how some people imagined the mindset of the Columbine killers, who were fans of the game Doom (source).
Is the game just a plot device, or is it a commentary on video game culture? It's up to you to decide. All that we know for sure is that the bad guys want to use Madaug's game to turn all teens into mindless killers. That's assuming teens would want to play this game, which involves an ancient evil, a fair princess, and a ton of other tired video game tropes. Maybe Nick gets angry because the game is so unoriginal.