The cover art is really good! The aviator cap is such a fun detail on Mystia. It isn't lost on the characters during the gameplay, either; the portraits are fun and expressive, and the game area is very easy to read.
I enjoyed the two songs as well! The main audio issue that I had was some balancing on a few sounds (ex: the alarm-type ones).
Aside from that, the gameplay itself is extremely intuitive thanks to the click-and-drag controls. The strategizing aspect is fascinating, and it seems easy to play - and challenging enough to encourage trying fast times on the stages. Another favorite part is how in-depth the writing is, exploring a wide range of pairings and dynamics (although I didn't expect Byakuren to be... quite that way ^.^;).
Overall, it's an excellent entry to the jam, and a very fun game to play through! Your team did amazing work!