Yeah I've been wishing I could go back and balance the audio better, the Title screen track is louder than the gameplay track, and the victory track is louder than either. But audio was stapled onto the game at the last minute.
It's for sure a very RNG dependent game. We did our best to get the game into a position where one can consistently clear the game once they know the layout, but like you said nothing is stopping a chain of bad luck where you miss 5 shots in a row and are blitzed down to 0 hp in just as many turns. Given a little more time we would have tutorialized a little bit more (but I'd also worry that too much of a tutorial would make it harder to just hop into a run quickly).
Thanks for playing! I'm glad you enjoyed and I'm happy you saw the 'secret' miniboss!