Argh, I didn't think this through when mapping the buttons for trying again. It's possible to do it by pressing "Enter" or "R" which will not make Youmu shoot though, if that helps ^^'
I realized towards the end that many of the design choices I took for granted for a normal danmaku simply do not work with the concept of "don't hit the boss", but it was too late in development to make any meaningful changes... So I let the player have an advantage by making the bottom and top of the screen "safe" during the first phase. Otherwise the fight was just impossible :x
Ooh, nice idea. Additional attacks to dodge instead of directly losing a life seems more interesting indeed ^^
Thanks for your comment, it gives me a lot to think about!