Exactly, that hiding guy can only be properly hit from behind. There is health, but it's not displayed, sadly.
First the design was for the player to die and restart the level, then it changed, that if you get hit, you get a point, and the more points you have, the worse is your end score, so the player could strive to do every boss no hit. The score recording is there, working, but we ran out of time to show it properly, so it looks like you taking bullets is consequence free.
Thanks for trying it out!