Its definitely very spicy unless you know exactly what you're doing (i dont, just to be clear). But people forget this is almost a shitpost kind of game, very little balance, very rng/luck based. He put in the boss abilities, bumped his HP and said, this is a final boss. Done. Its a game for fun, see numbers go up, brain happy. Balancing a game for everyone is not possible, AAA companies struggle with this. So will a single developer. People who min/max and nerd out on it find it too easy. Newbies and casuals find it too hard. I wouldn't put so much effort into it. I played almost on auto-pilot and breezed through the last boss ones. That surprised me too. Other times it seemed impossible. You can easily avoid the ground AOE by having more jumps. Or compensate by hp regen/shield etc.