How Video Game Jingles Work

pizza tower has some great jingles...

Something seems to have perhaps gone wrong with audio processing on this video. For several of the example tracks, most obviously Breath of the Wild and Animal Crossing, there's some strange echo in the audio, like the track is present twice on the timeline with a slight delay. I originally thought YouTube was interfering somehow (stable volume, argh) but it seems to be present even with all of that turned off, and not on every song. Were you experimenting with a new audio processing setup?

This is great. I wrote a composer for a TV show recently about whether his jingle was an intended homage to the FF victory theme, and he pointed out (as you did) the ubiquity of the I -> bVI -> bVII -> I cadence

This was really cool!