Very nice soundtrack, enjoyed a lot its catchyness and sound variety !
The instruments chosen for the tracks is very nice (loved the Yes-like B3 organ sound on Whimsical Ferrous Blossom for example), and the tracks, although quite short, have a lot of great sounding variations throughout.
It reminded me of the musical style of tracks from Mother 3 which works nicely for the rhythm game you had in mind (I can imagine doing the rhythm attack combos from Mother 3 while listening to your tracks).
I liked all of the tracks and all of them are top notch, although I feel that Whimsical Ferrous Blossom is the standout track for me (has a great rhythm and intensity), so great job for your album !