While both series continued to develop titles in this format, the concept of Metroidvanias started to gain more traction when other parties began to develop games in the same style.[1][10] Cave Story (2004, Microsoft Windows) developed by Daisuke Amaya as a homage to Metroid and other classic games; the game was critically praised showing the scope of what one person could do, and highlighted another take on the Castlevania and Metroid games, as well as vitalizing the 2D platformer genre as a viable indie game format.[1][11] Shadow Complex (2009, Xbox 360) by Chair Entertainment was developed based on the premise that Super Metroid was "the pinnacle of 2D game design". The game received highly positive reviews, and remains one of the best-selling downloadable titles on the Xbox 360 service.[1] Due to games like these, the Metroidvania genre began to take off in both publisher-driven and independent games development.[1]