The gameplay originated with a tech demo by Naka, who developed an algorithm allowing a sprite to move smoothly on a curve by determining its position with a dot matrix. Naka's prototype was a platform game with a fast-moving character rolling in a ball through a long, winding tube, and this concept was fleshed out with Ohshima's character designs and levels by Yasuhara. Yasuhara originally intended to work on the game for three months due to the delay of his planned move to the United States by the outbreak of the Gulf War, but was engrossed in the project for nearly a year. His designs for levels were intended to attract both hardcore and casual gamers by integrating occasional challenging set pieces into the mostly accessible level design. The color scheme was influenced by the work of pop artist Eizin Suzuki, and the aesthetics of Green Hill were influenced by the geography of California.