This CD actually completes missing tracks which were not included in the OST (MUCD-1202). Here, we find the majority of songs (insert, opening and ending themes), as well as some BGM composed by WADA Kaoru (Vampire Princess Miyu, InuYasha, 3x3 Eyes, Lodoss War TV, Princess Tutu, Harlock Saga OAV).
My favorite tracks are: "Luna" (n°6), a recurrent theme dedicated to the mysterious girl Luna, very sad and beautiful melody played with strings, harp and oboe (hautbois), and accompanied by a female chorus. Then, "Sky" (n°7), insert song sung by MIYAHARA Nami (Janice) in episode 8, is amazing and so peaceful! Following of "A Path", but here in instrumental version. It is too bad that the voice of Nami is changed to harmonica. However, the music stays awesome.
In short, this mini CD (only 35 minutes!) is targetting, before everyone else, Casshern Sins fans. The others will have no interest to get it.