SimTunes is a children's software toy designed by Toshio Iwai and released by Maxis in 1996. It involves painting a picture using large pixels, where each color represents a musical note. The player places up to four different-colored Bugz, which represent musical instruments or vocal syllables, on this picture, and can change their starting directions and relative speeds. The Bugz crawl over the picture, playing notes corresponding with the colors; and they turn, move randomly, or jump in response to function symbols that can be added to the dots.