I think Illusion of Gaia has the weakest soundtrack from the Quintet games, too, since few tracks stick out. Lively City is nice, and Longing for the Past isn't that bad. Beautiful World is an enjoyable overworld theme, but I'm pretty sure the game uses a point-and-click system to travel between different locations, so it's a bit odd for it to be so long.

Terranigma's soundtrack is probably my favourite out of Quintet's games (although I haven't listened to Granstream Saga), so I look forward to the next review!

Some typos:
"shifts between ideas to quickly" should be "shifts between ideas too quickly"
"greater development of its tracks then ActRaiser" should be "greater development of its tracks than ActRaiser"
"this took longer then I thought" should be "this took longer than I thought"
"more consistent then either" should be "more consistent than either"