Press 1 for Invasion

Matt, who is ten, would really like a cell phone like his best friend Gene has, but his parents won't agree. When he finds a cell phone on the sidewalk, he takes it home and tries to get it to work. The only thing he can get it to do is to take pictures, and he snaps one of the school crossing guard, Mr. Mackintosh... but it looks like a monster! Gene doesn't see this at all. The phone never seems to run out of charge, but has an alarm that seems to be going off. When Matt realizes that a cafeteria lady, Mrs. MacGillicuddy, is also a monster, he asks her some questions. She admits that there are aliens on Earth, and they do want to occupy the planet so that they can eat people, but she herself has become a vegetarian, and is willing to help him. Matt is able to see the monsters because he has heterochromic eyes. He briefly tries to alert Principal Delgado to the invasion at his school, but Matt is dismissed as unstable and referred to the school pyschologist. Mrs. MacGillicuddy is part of the foreign service, and knowing how to cook humans is part of her mission, but she thinks that if Matt can work to prove that humans aren't worth eating, the invasion will not happen. Along with classmate Marcella, they try to come up with a plan that does NOT involve Marcella and Matt giving up an ear, some blood, and a few bones so that Mrs. MacGillicuddy can serve appetizers to the visiting aliens. They visit her eerie house to work on plans, and a report is made to General Guggenheim that the food source is ruined, but that isn't enough. Will space aliens take to spy or seitan meat sources more readily than humans do and leave earth alone?

What worked:
Matt is an unlikely hero, as he doesn’t seem to have any friends beyond Geno. However, he only hangs out with Geno because of his amazing collection of comics. One of Matt’s redeeming qualities is his kindness toward the lunch ladies. Most of the students make fun of them, but Matt takes the time to talk and to show them politeness. He feels his parents are overly cautious when they won’t get him a cell phone, but it reinforces the idea that he’ll be chosen to save the world.
Young readers will probably be shocked to learn the aliens are invading Earth, because humans are a delicious source of meat. The lunch lady reveals the plan to Matt, and he’s creeped out by the idea of being eaten by aliens. She talks about it matter-of-factly, she compares eating kids to eating veal, and can describe the cooking process in her role as a chef. Even though she insists she’s now a vegetarian, Matt’s still uneasy at how casually she can talk about eating humans. He learns the school crossing guard is another alien who is looking forward to a delicious meal.
Matt’s eyes are two different colors, which is the reason he’s the only one who can see the aliens in their true forms. The crossing guard is an immediate antagonist, and his rhyming comments to students are creepy. He figures out Matt has seen him in his true form and starts becoming more aggressive. The only way Matt can avoid the guard is by taking a route with a dog that scares the heck out of him. The crossing guard isn’t always present in the story, but his threat is constantly in readers’ minds. So, they’ll anticipate a confrontation between Matt and the crossing guard at some point, even as Matt is trying to stop the alien invasion. The plot's climax offers more than what's expected.
What didn’t work as well:
The physical appearance of the aliens may confuse some readers. They have seven tentacles and multiple eyes, but humans see them as a normal man and woman. They haven’t transformed or anything; they just look different. Even Matt finds it challenging to mentally reconcile that the woman he sees walking across the room is actually slithering across the floor on tentacles. It’s helpful that Matt wears special glasses later in the book, so he can describe to readers what’s really happening.
The final verdict:
The plot has a fun blend of humor and adventure where two young kids must save the world from invading aliens. The danger of being eaten is a curious twist to the conflict and adds novelty to the story. Some of the silliness may not appeal to everyone, but I still recommend you try it for yourself.