As expected, a lot of people in this thread are giving "valuable" advice about his art style. Jeff's self-ironic way of saying the game looks like crap and calling his art style inconsistent seems to have set the tone of the conversation.
Having played through the Avernum trilogy last year, I don't think the art style is inconsistent at all, especially considering how old some of the assets are. Please have a closer look at some actual screenshots from a recent Avernum game[1] before providing your invaluable input on how he should manage his game art.