Touhou: Genso Wanderer

The original world of Touhou was created by ZUN, a one-man dev team who has handled the game design, scenario writing, programming, character design, and music production for over 15 entries into the universe. Though he originally created Touhou back in 1996 as a way to create his own game music, the series has become a bit of a phenomenon thanks to the Play Doujin! scene that has grown around it and fostered a plethora of fan-developed games like Touhou Genso Rondo.