Several things define "chiptune"; an underrated one is the channel restriction. Which this track bypasses by being made on… 2 Atari POKEY chips, a configuration easy to set up in modern trackers but historically meaningless. The only way to play this song on period hardware would be to MIDI-sync two Atari 800s and have them play a duet.
A neat, melancholy glimpse at an underexplored part of musical configuration space: