Galaxy Force (Sega Master System)

FM Soundtrack
FM sound support in the Master System was only released in Japan and South Korea. This game was developed by a Japanese team under Activision's coordination and so has FM sound support, but was not released in either Japan or South Korea, rendering it totally unused. (Whether or not the game was planned for a Japanese release is unknown, but the Master System was killed in Japan as soon as the Mega Drive was released.) Support is fully implemented and works (you can hear the FM soundtrack in an emulator).