To start with, Petersen's artwork for this comic is phenomenal. It has a storybook feel to it, but with a depth that's reminiscent of Medieval woodcuts. It's a pleasure just look at it. 
 His storytelling is also interesting, with each issue being a self-contained story, and each new chapter advancing and reiterating the plot. 
 Because of the small pages, Mouse Guard can feel a bit shallow, but when you look at the full story, its beauty and depth comes alive.