Climbing has been less important as the franchise has progressed, but I don’t remember it being a challenge even back in the Ezio games. Is that just my memory smoothing over the differences in games? They’ve changed the control scheme a few times and experimented with the idea of “parkour up/parkour down” buttons, but going up was still pretty much holding down a single button and pushing the control stick up. I remember you occasionally have to move around to another side of a tower where there were more windows, but it never felt more challenging in a meaningful way than it does to me as recently as Origins.