I am really impressed by physics and don't understand how it works :)
I think it can be easily turned into a Twitch integrated thing where the cubes are SpriteRenderers and display emotes that people write in the chat!
Hmmm, are you sure? I checked again - stayed in the start for a minute and there was only soundtrack, yes, but it is not the soundtrack I am talking about. It happens only when you walk, and it is very inconsistent, random. Sometimes happens twice, sometimes not at all for several of seconds. This sound reminds me of billiard balls, when they hit each other.