Parkour looks like it's taken at least 3 steps backwards. I always found it so frustrating to repeatedly press up against a wall instead of running up it, or leaping across little gaps instead of just walking the railing, or doing the little run up the wall and fall back down even when it's clearly a climbable surface. It was slowly becoming less common in each game, but this one just looks like pure regression in terms of movement.
Perfected is a stretch. I still play unity a lot for the black boxes, and it has a ton of misreading input issues, but they were definitely on the right track with beautiful animations and good transitions. The problem with Mirage is that its literally just Valhalla under the hood, having been originally planned as a dlc campaign. Valhalla being a viking sim with the worst fucking stealth system in the entire series and no parkour to speak of in rural Viking Age England.
This game is a huge miss for Ubisoft and might actually sink them as a whole. They're currently back against the wall financially speaking, having canceled a plethora of games to save money, and cannot afford to be fucking up their flagship titles this bad. Wish I would miss them, the early Ubi games like R6 Vegas, Splinter Cell, The Settlers, and Ezio trilogy basically shaped my childhood.