I checked the game credits and the booklet credits.
The perfomers are the usual ones (I mean Feeder, Ash, Grand Theft Audio, Overseer and Daiki Kasho).
I'm not quite sure for the intro : credits are not that explicit and I can hardly hear the difference between two techno tracks. It could be Daiki Kasho, or "Moon over the Castle (A-spec mix)" by Masahiro Ando, which is credited but doesn't appear on the music selection screen.
Hope it helps...