fwiw here's my Squeak Squad guesses too... the overwhelming supply of Ishikawa makes me think nobody else was involved. Composers only offering one or two songs for a game isn't unheard of, but it is relatively unlikely, and not something I've noticed in other HAL game soundtracks.
Nonetheless I did think a few were more likely to be Ando, and that one Sakai tune mentioned before.
also my tags suck