 Developed for the Super Nintendo Entertainment System, the prototype was based on "chanbara" action, a type of Japanese sword fighting.With "Super Mario 64", Koizumi became assistant director and animated the 3D models, among others working on Mario's swimming movements in cooperation with director Shigeru Miyamoto.While developing "Super Mario 64", Nintendo's employees devised rough concepts of a three-dimensional "The Legend of Zelda" game with a bigger focus on puzzles and less pronounced action elements.