This is a fun concept! There are plenty of games about the magical girls starting out or at their peak, but not as many about what comes after.
The art is really good, and the music fits well. I'll echo what others said in that it wasn't always easy to tell who was talking, particularly when (several?) off-screen characters started to chime in. The battle was a neat idea, but I wasn't really sure what was happening, and the mechanics of the fight were way less interesting than the characters just talking.
Overall, this is a cool and unique entry that I enjoyed quite a bit. I'd love to see it expanded upon.