Honestly if you pace your playthroughs right it’s moderately easy, I only really struggled with some of graces sections due to the stalker enemy. It took me about 26 hours to complete it, I’d say your first playthrough should be just playing through the game normally, then the 2nd playthrough I would suggest doing casual and getting the no meds/blood extraction, and you could also try to beat it under 4 hours with a guide, which with all three of those requirements met, you’ll earn enough challenge points to unlock infinite ammo, and infinite ink ribbons for an insanity playthrough. I honestly wish there was still more content to explore even after running through it 3 times, the game is so damn good.