Thank you for noticing some of the details. I spent most of the time thinking of patterns and timing it to the music BPM. But there are also the little things like blending in friendly shots and friendly ships into the background color so everything could be read easier.
It is not an easy game at all. It also took me several tries to beat the March 30th version. The July 31st version is way harder (no AI teammates) and I didn't try to attempt it more than a couple of times, but made sure it was possible in a dev debug mode if you are good at dodging. That's for the hardcore SHMUP players. But I agree it could be more forgiving and have lives or health.
Thank you for the review!