This is a fabulous book. The story is gripping, the art is good, and the characters are engaging.
I found the dialogue to be consistently natural and believable, and all the soldiers are likeable. The Big Bad Evil Guy is very cool, and he's introduced a little at a time, which makes him even more memorable.
The artwork appears to have been done with watercolors, which I happen to really like. It sure looks like it was done using real paper and paints, which is unusual and refreshing in this world of 3d computer artwork.
I had to read it a couple times to "get" everything that went on, but it's definitely worth a reread just to see it again.
It also cries out for a sequel, which I really really hope Pearson writes at some point. I'll be first in line to buy it, if and when.