Your lover Gwendolyn is dying, cursed by the evil wizard Sfax. You must fly to the Red planet and confront Sfax, for only by killing the sorcerer can the curse be lifted.
Mach 3 is a pseudo-3d shoot'em up. The player controls a space fighter (seen from behind) and battles hordes of enemy aircrafts, dodging meteor showers and trying to destroy ground targets to regain fuel. The player can try to fly under arches to increase her score, but must look out for magnetic mines. Once in a while a heavily fortified bunker appears, it's the entrance to the sorcerer's domain. If the player manages to get in, she must then confront one of Sfax's incarnations.