It's a collection of interesting assembly snippets ("gems and riddles" in the author's words) presented without commentary. People have posted annotated "solutions" online, but figuring out what the snippets do and why they are interesting is the fun of it.

It's also available as an inscrutable printed book on Amazon.

It's a chiptune-style xm module, "Funky Stars" by Quazar: https://soundcloud.com/scene_music/funky-stars

Keygen music will always have a special place in my heart. This is a good one.

I do wonder who was the first cracker that thought of including a keygen music that started the tradition.

I also miss how different groups competed with each other and boasted about theirs while dissing others in readmes.

Readme's would have .NFO suffix and that would try to load in some Windows tool but you had to open them in notepad. Good times.