Zero Tolerance Underground

Zero Tolerance Underground, also known as Zero Tolerance Origins, is an aftermarket first-person shooter originally developed by Technopop. An official Mega Drive port of Zero Tolerance which includes the nine additional levels from the game's planned Mega-CD version was published in 2022 by QUByte Interactive as part of QUByte Classics: Zero Tolerance Collection by PIKO for the Nintendo Switch, PlayStation 4, PlayStation 5, and Xbox One, and additionally saw a cartridge release in Europe courtesy of Strictly Limited Games.

Although the title screen is the same from the original, the Options screen includes an image of the Fighting Pad 6B alongside descriptions of the extra commands.