Spheres of Chaos is a multidirectional shooter video game, created by Iain McLeod, with basic gameplay similar to the 1979 arcade game Asteroids. The game has bright colours and patterns, with many enemies on screen at once. The audio is similar to that of Robotron: 2084 and Defender. It was originally written for RISC OS on the Acorn Archimedes and released in 1993. In the 2000s it was ported to Linux, Microsoft Windows, and PS2 Linux. In October 2007, Spheres of Chaos was declared freeware.