Empire State is unique, as far as graphic novels go, not so much in tone or story, but because it does some interesting, if simple, things with color.
The story is about a 25 year old Asian guy named Jimmy living in Oakland. He has prospects of becoming a web designer of sorts, but seems stuck in a life not suited for such ambitious pursuits. He's actually very easy to relate to because the entire story has a post-college lull feel to it that has become so common in the post-college generation. He has a friend named Sara who he is in love with. When she moves to New York, he decided to travel to the "Empire State..." and visit her.
This is where the color patterns become interesting because every time we're sent to the past, Shiga colors the entire page with a sort of red theme, and every time we're pushed into the present, it's blue. This may not seem like such a big deal when you consider how many graphic novels are published in full color, but it makes reading an otherwise black and white comic slightly more interesting because you can immediately know at what time period the story takes place just by looking at the color. This also allows Shiga to jump around however he likes, which maybe improves the written narrative.
The story itself is subtle but charming, and as funny as anything I've read in recent memory. Jimmy himself, without realizing it, is a born comedian. The strangest thing I found while reading the story of these two characters was how unappealing Sara was, and I suppose this could be refreshing because it doesn't thrust her into the role of manic pixie dream girl or muse to Jimmy. She's boring and unattractive and doesn't necessarily treat him all that nicely, but he likes her anyway. His naivety is realistic and sad and completely believable.
I think Empire State, and probably Shiga in general, would appeal to fans of the Scott Pilgrim series. Though O'Malley has a more fantastical approach to his storytelling, the styles are quite similar.