Seems there's some music by Mitsuda that didn't make it onto the OST:
http://www.youtube.com/watch?v=s0g0N7lGtPE
It's interesting to note that this video is taken from the game's sound test--which clearly credits Procyon Studio for the music. I wonder if that means the other composer for the game was Shunsuke Tsuchiya? The game was released in 2003... when did Tsuchiya join Procyon?
And now I'm wondering if there's any more unreleased Mitsuda music from the game...