Shelley has said that the key to the success of the games was its innovation, rather than imitation of its peers. He also claimed the unique elements in the games "helped establish the reputation of Ensemble Studios as masters of the real-time strategy genre." Mark Bozon of IGN wrote in his review of "The Age of Kings", "The "Age of Empires" series has been one of the most innovative real-time strategy games for PC in the last decade or so." Gamenikki called Ensemble Studios "the developer that started it all" when they talked about how much "Age of Empires III" had done to advance the real-time strategy genre. Shelley has acknowledged the success and innovation of "Age of Empires" helped to ensure Ensemble survive its early periods since startup. In 2005, Shelley complained of critics holding an "innovation bias" against the series; citing the 60% score from "Computer Gaming World", he said that despite "Age of Empires III" being "perhaps the best selling PC game in the world", reviewers expected "something really new", and rated it harshly.