Yeah, the beginning is stupidly hard tbh unless you are level 8 or above going into it. You have no Atreyus to stun things because Kratos tells him to stay back (same as the original game) and everything one shots you pretty much. That said my first playthough I killed the Valks at level 6 and then start NG+, so was at a huge disadvantage, the NG+ Valks are different so even if you learned the patterns on the originals, they move differently and are a little quicker. If you like a challenge and don't mind dying alot its for you.
It gets a little easier once you have Atreyus to shoot stuff but because his arrows don't unlock until they unlock normally in the story its still pretty tricky. One you get 2/3 of the way through and have those arrows back and all the new gear, the difficulty eases off and only the Valks are a challenge, you'll still die occasionally but with the NG+ gear and a high level, the mid game is not as bad as DS, probably a little more difficult than UH on Horizon because the fights are in more confined spaces and are harder to avoid. The fights with Baldur are pretty straightforward enough but they take fecking ages so much so during the last boss I was tempted to switch it off and not finish it a 2nd time, because there was no way he's was gonna kill me as he couldn't land a hit, and I was battering him for very, very little damage.
Oh and special mention to the elevator part where you have to kill the enemies fast or it collapses... that's tough as hell.
That said I didn't play Horizon on UH to completion (only early game) because something else was released at the time so it may be balanced better. It's worth playing for the new Valk fights alone if you like a challenge.