That was amazing, really great song & visuals too. Takes me back to the days when you couldn't close the keygen because the midi playing was such a banger.
[0]: Soundtracker, the tracker that started this all: https://en.wikipedia.org/wiki/Ultimate_Soundtracker
I'm still since then always assuming the above when someone says "MIDI music"; they really mean "really basic/simple music" or just straight up "chiptune" sometimes.
It has nothing to do with MIDI really, just a misnomer.
The same behavior could be (also was) teased out of a MOD player if you choose samples with a handful of sample points, like 12. You could also draw up a sawtooth in paint and use that as a sample. These are down-to-earth honest true Scotsman chiptunes.