Well, I've tried it earlier since i found it through google. The only problem i got with it is that it complains about that the files is in a language that it doesn't know (japanese obviously >_>). Got no idéa what the files are... when i go into "properties" on one of them it says "DAT-file (.dat)" so I would guess that it's a Digital Audio Transfer file?
It's a game with almost only .dat files. The only files which isn't .dat are the .exe and the config file (.ini) which looks completely screwed when i open and read it. The game apparently does fine with a non-understandable config file.
PS. Check my avatar. Good work, HG