THat video surely is a good teaser!
Loved the bullet rain that happens towards the end, but with that spaceship shape, it feels a bit hard to imagine how gameplay is.
If I may suggest something, I think it'd be great if you reduce sprite sizes a bunch and allow for more room. The sprites, especially the main one, look really too large, and not fitting of a Danmaku-type shmup.
Also use case studies to analyze bullet-rain patterns as the one in your prototype look prone to be impossible to pass unscathed, I'd recommend any game by Raizing or Cave from the late 90s.
Anyway keep it up! I am particularly excited that you are planning to have a CD32 version. Our CD32s need more love