The last news I heard about it was from DeJap in 2003. I'm sure someone has tried since then, but I can't think of anyone offhand. Obviously a great many things have changed in the last decade and what must have once seemed like an insurmountable task is something that I'd imagine could be done. According to the old DeJap website there's a PS1 and Saturn version as well, but the Neo-Geo is the easiest to hack. I don't know if that's still the case at this time (with PS1 emulation and tools being more readily available) but I'd obviously defer to Dark Force's knowledge of the subject.