Apparently, the soundtracks behind the games Mini Metro and Mini Motorways by Dinosaur Polo Games were procedural, designed to play out in reaction to player decisions. I found this out while trying to search for the games' soundtracks, only to be met with a confusing lack of results. Turns out, the whole musical component of the games are comprised of samples and only trigger in accordance to player activity, making for unique listening experiences with every session. That's pretty sick! It's a shame that I can't just pop on the soundscape for easy listening or as a background jam for a video essay (as I'm working on now), but with such an interesting experiment at hand, it makes the lack well worthwhile, in my opinion.