Of course, much of this book is over the top. Gizmo wears glasses, orders things off the internet, and manages to get aloft in a drone at the school pet parade. The ordinary life of Jasmine and Elliot's family is a nice foil for the celebration of evil genius, and every day details about meals, school, and family chores makes a good argument that Gizmo's exploits are absolutely possible.
Jasmine's jealousy over Emily and her pet rings absolutely true, and Elliot's reluctance to get involved in her plots is something that older brothers will definitely recognize. My favorite character is Abuela, who is the only one who really seems to understand that Gizmo is actually a threat. She keeps telling the family "Yeah, the guinea pig ordered a drone on my credit card", but they never believe her. Even more endearing is the fact that Abuela LETS Gizmo order the drone and even unpacks it and makes sure it is available to him when he needs it.
Readers who enjoy Birney's Humphrey books, O'Donnell's Hamstersaurus Rex, or Reiche's I, Freddy will appreciate this series' use of a guinea pig rather than the overworked hamster. I can't think of too many books that include mini pigs, either, and Wedgie is in a class with the movie character Bolt in his insistence that his cape makes him a super hero!