I am listening to this now, just got it yesterday. I really like it. It's a bit quirky, and at times very mellow, vaguely jazzy, vaguely new-agey (whatever that means). The mellowness doesn't take away from the interesting rhythms and melodies.
There are some pieces which are not solo piano (maybe about 50% is solo piano), including one with a Shakuhachi (Japanese flute) which is wonderful. If you've never heard a Shakuhachi, it's made out of a single piece of bamboo, which gives it a very rich and natural, earthy and at times unearthly tone, not comparable to a flute or other metal instrument. Its sound is more like fresh cream than skim milk. The shakuhachi is usually used in traditional Japanese music, so it's nice to hear it paired with piano in a modern composition.
There's also a piece with a rapper (need to listen to that again, can't comment at this time!) which is surprisingly laidback, and a few pieces with cello and other strings or percussion.
I think past criticisms of "Asience" are probably appropriate, but at the same time I find that piece very compelling, and this CD includes two versions of it. It also includes "Merry Christmas Mr. Lawrence," which is about 10 years old, but the arrangement is new and is performed by Mr Sakamoto himself of course.
If you're interested in Sakamoto's music, I highly recommend this one!