No, I'm not on Stack Overflow. How the music works is that it uses embedded VBScript (scroll to the bottom). The technique to embed is from here https://stackoverflow.com/questions/9074476/is-it-possible-to-embed-and-execute-... (the last bit of the first answer). I define macros that use it to play music via CScript. In terms of a cool Batch, you should try this game instead. It has much better code, and showcases how I created the graphics more.
To create the diferent colours and stuff, I use VT100 escape sequences, which is Windows 10 only and makes it a lot easier. You can check them out here https://docs.microsoft.com/en-us/windows/console/console-virtual-terminal-sequen.... Also, I would not recommend creating multiple folders in your game to simulate a dungeon. If I were you, just create some sort of variable that stores what goes into what, and it will be much easier from there.