This admittedly isn't my type of game and after several attempts, I gave up on the final boss (though I sometimes launch the game again for another try).
The core idea is interesting. I would like to see further innovation to better flesh out the idea of bullet hell SRPG; right now it feels like more weight has been placed on the bullet hell than SRPG. Adding unit proficiencies could add some strategic depth and customization. There may be a limit to this, as longer levels of chess-boxing could become exhausting.
Something which isn't always thought of, but the audio cues were excellent. I exclusively depended on them to solve certain patterns.