As well as being able to 'rent' disk games, the Disk System could also connect to a couple of inputs on the system to play audio, which means the FDS versions of eg. Zelda and Castlevania have another track available for sound, so their tunes are particularly banging on this system.
In the west, those inputs were repurposed for the 10NES anti-piracy system, so we got worse music and a console that was less reliable, particularly with age. Yay.
Mark Z. Danielewski for the win. House of Leaves is superb; 50 Year Sword is interesting, but doesn't quite scratch the itch. I see he's got something new out this year as well, will need to check it out.