The game did not start out as a "Mario" series game and the first prototype featured a generic kart racer character; the team decided that characters three heads tall would best suit the design of the karts. They did not decide to incorporate "Mario" characters until a few months into development. The choice was made after the development team when observing how one kart looked to another driving past it, decided to see what it would look like with Mario in the kart. Thinking that having Mario in the kart looked better than previous designs, the idea of a Mario themed racing game was born.