Definitely a solid first Danmakufu script. Music is the strongest part, but artwork and danmaku is also quite well-done, albeit simple and unpolished. I've caught wind that the programmer (ABootToTheHead) only had 4 days to learn to use the engine, and for that reason I highly applaud how much they were able to learn and utilize in such a short time frame.
If you ever do plan to update this game, I would love to playtest it.