I never got past the first boss. Even once when I had six full hearts and longer invincibility from taking damage, I came just shy of getting it half-way down on its life. It’s spongy, it cakes the entire screen in shit that tries to kill you, AND enemies spawn while you battle it. Some of them, like the guys in the minecarts you see, drop bombs that give you even more shit to dodge. This shit isn’t fun. it’s a war of attrition.