The Nintendo PlayStation contains an undumped 4-bit NEC MCU for its CD controller. Once that EEPROM bit-rots (it's already past its guaranteed lifetime), the SuperDisc BIOS cartridge will no longer boot as-is. The two fan-made games ported to the CD-drive will no longer function at that point, and we won't ever be able to directly fix this, only to hack around and approximate the original functionality.

I imagine this won't be a significant loss to its new owner, but it's still unfortunate.