hello i am the friend!!! let me elaborate for anyone else who feels like tackling this...
the MMA files for this game are in a later/more elaborate format than the ones assumed by the BMS scripts:
- first there's that big mystery header, starting with the expected string 'MMFW Sounds'
- then there's the file offsets
- then the file names
after that, the existing scripts expect the file data to start... but in this case, there's a lot more going on before the beginning of the first actual file payload!!
here's a screencap of FURBYSD2.MMA showing off what i've found: https://imgur.com/a/RlTLcs8
- the part highlighted in yellow has 4 bytes per sub-file in the blob, each starting with 0xB3 (same in FURBYSND.MMA). I have no idea what these are and even after i blanked them out completely the game played its music without complaining -- checksums perhaps? if so, the're ignored
- then there's a spacer of 0x00 07
- then there's 1 byte for each file in the archive (highlighted black) -- by fussing around with them and running the game a few times, I determined that these are flags describing the sub-files bitrate and such -- and it seems like bit && 4 determines what format the file is in (i'll get to this in a minute)
- THEN, between that, there's a desert of i don't know what, before the actual file starts at the first actual file offset, 0FFE (not highlighted)
ULTIMATELY, i got the files to sort-of extract with the millionaire3 BMS script, but the AIF files themselves are ALMOST completely junk -- if we force them to play as raw audio, the music and sound effects are vaguely identifiable but garbled. I assume they're compressed somehow, but comtype_scan2 couldn't identify the algorithm either. when i turned off the 4 bits in the black highlighted section, the game tried to play the audio as uncompressed and i got the same staticky mess from the game itself!
any insight on this? does this archive look like anything created by a human being or did some obscure madman develop this file format?