Slitherine

All of the files are in uexp format. Unknown.

This is Unreal's asset format. I think, it should be possible to create such files if you install the (free) Unreal's editor, but I don't know exact steps how to do it with a single file (in normal development all game's assets are "cooked" all together).

I don't know anything about editing files with unreal but I will try, keep the same name file while changing the content. The other matter is how to add songs if it is possible.