What a strange casting. It's split into two very different groups. Tamura Yukari and Kanai Mika have exaggeratedly cute voices whereas Shintani Ryouko and Sawashiro Miyuki have carefree kind of voices. I'm not downplaying the carefree side at all. Well, more on that on "Yami Nabe CD" listing.
This CD isn't all that great, overall, but there are some neat songs still, like both of the group songs. I think "out there whackiness" is a requirement for good GA songs, and some of the songs on this CD are too... normal.