Better than a simple good vs. evil book, The Gaia Wars encompasses the more complex aspect of man vs. nature. Included in that "nature" are the humans who still feel connected to and moved by it. One of these humans is the main character, Warren, a boy of 13, who feels compelled to protect the land he's come to love from development and destruction.
Warren is a typical kid in terms of his mischievous and exploratory nature, but he is also revealed as sensitive, caring, and wise beyond his years. The bad seeds of the book - the power-hungry and money-grubbing Finleys - appear a bit two dimensional, but they don't deter from an overall compelling story - the fight for Mother Nature herself.
The only downfalls I found were a couple of spots that were a bit frustrating in terms of not being believable enough for me. SPOILER ALERT!: For instance, Todd Jr. is described as a fat and out-of-shape kid, yet in one scene, he is able to shadow Warren and his friend Sean, riding his bike up a mountain trail and having time to flatten the tires of their bikes once Warren and Sean set off on foot, and still be able to keep up with their pace. (And this with Warren and Sean having to stop and take breaks even though they are seasoned hikers.) It also didn't make sense that Todd Jr. basically outran them down the mountain as well. Although, I guess Sean did conveniently trip; how Todd Jr. made it down without falling is beyond me. But anyhow...
The history of the alien race in The Gaia Wars parallels the path of doom our own Earth is gliding toward as human beings begin to rely on and become dependent upon technology, and seem to care more about conquering and controlling nature than living as the biological creatures we are. This is a good book for kids of all ages to read for a better understanding and appreciation of the natural world and how it can be just as fascinating and entertaining as any TV show or ATV (in a different way, obviously).