So today I started looking at Assault's files between the Japanese and English versions of the game and decided I wanted to attempt to make an undub, to restore the Japanese VA as well as the more expressive animations that were diluted in the English version. Problem is, it seems absolutely nobody has any sort of information on the game's internals from a cursory glance.
I've figured out a few things at least - the FPC files seem to be archives containing voices, animations, textures, and subtitles, used for cutscenes. I've had preliminary success swapping *some* of these out - a handful of cutscenes in the game are prerendered video files, and their FPCs only contain subtitles, so this was really easy. However, replacing other FPCs results in something very interesting, but not the desired result - what seems to be an early English localization, riddled with typos and incomplete animations (likely mandated by the executable telling the game to load English data.)
What I would like to do is find a way to extract the individual components from each FPC (VA, motion, textures, and text) and replace the English VA and motion with their Japanese equivalents. However, I'm very inexperienced with something as complex as reverse engineering a relatively unknown format, so I figured I'd see if anyone else is interested in possibly helping.
Here are the FPC files from both the NTSC-U and NTSC-J versions of the game, if you would like to contribute.https://mega.nz/#!mVtDkYzB!SnoCVTMl1cIWvyaoHdoB6LvDPLISh3UhIEHaJK54DBQ