The chill music you are talking about, is probably not mine.
There was another artist who made an EP of sorts, that was put into the game.
No idea who he is anymore, I don't quite recall. As for download links, I know in previous versions people probably had access to it and even I had the link to his EP at one point.
But I do not have it anymore, the best thing I found was some of the music on YouTube as Toribash OST. Sorry I cannot provide something better, but if I find it again I'll PM you.
I made some tracks but those aren't played as often as the original OST.