I'm still in the midst of playing it. And it depends. The difficulty and frustration is completely counteracted with the ecstasy and feeling of reward you get when you actually defeat a boss. It's hard but I think people oversell how difficult it is.
Sure I die a lot, but unless you hate challenging yourself, the surreal, gothic beauty of the game (that only gets more beautiful the more chapters you go through) and the polished mechanics and imaginative enemies just drive you to push on with determination and really admire the world that's been created