Pioneer Plague is a game designed by Bill Williams for the Amiga computer and published in 1988 by Mandarin Software and Terrific Software. It is one of the few games to use the Hold-And-Modify display mode of the Amiga for in-game graphics, a mode which allows thousands of colors to be displayed at once, but in a format that's better suited to static images than moving objects. It may have been the first commercial game to use Hold-And-Modify. Pioneer Plague was not ported to other systems.
Williams also wrote the 1986 Amiga game Mind Walker.