Very cool. I'm not super familiar with the genre (I tried to circuit bend my first gameboy and a couple of other things and that was about it) but it seems like I only hear NES, GB or Genesis-sounding chiptune songs, never SNES to the best of my limited knowledge. Are those just easier mediums to make original music with?
If I had to guess, it's probably that once you move into sample-based synthesis things get a bit less characteristic-sounding and are probably too flexible. There's not a whole lot different acoustically between SNES and, say, ScreamTracker or FastTracker.
The chiptune sound is pretty much defined as being made up of simple fundamental waveforms and basic frequency modulation.
It's probably because they're more limited. You can make anything come out of a SNES. They say that when Shigeru Miyamoto heard the theme song from Plok he called bullshit on it.
Haha Plok. I used to have that game. It was actually pretty good (and difficult as fuck) for a platformer if I remember, but I've never heard it referenced anywhere by anybody.