Oh, the game, you ask? It sucks elephant dick. Vanilla TW3 plays like Metal Gear Solid V in comparison to that.
I don't know where to start, so I'll do it by saying that the game feels like some Mass Effect ripoff (no coincidence in 2011), and ME is easily the one of the most annoying and boring games I had the displeasure of playing. Due to that, the basic gameplay of navigating through the world, at first promising due to graphics (which actually hold up extremely well in 2021, credit where credit's due), shows its stark reality the moment rail-roaded Prologue sequence ends and you leave Flotsam's gates.
Starting from here until the end, all 3 Acts and their level design consist not of those wide open spaces of TW1's countryside, swamps, and wide streets; but extremely claustrophobic terrains you have to navigate in a "winding road" manner only in one proper manner. Maybe there's less backtracking than in TW1, but it sure doesn't feel any better. In 1 you (mostly) could just freely run around said spaces, and that atmospheric Vizima Cloister district, which admittedly added to its charm of finding new things in the old places as the Chapters went by. Here you'll bump into an invisible wall every 5 meters, starting from "dense" forest where between 2 trees there are bushes you absolutely cannot cross, all the way to Loc Muinne, having to find a way around that fallen slim pillar because you absolutely cannot jump.
It's further hindered by the main mechanics, which are just bizarre. I just finished mentioning how you cannot jump through a 50cm ledge unless p r o m p t e d, and you have no excuse of Aurora engine because they have their own RED Engine now. Starting in Flotsam, in order to navigate around the forest, you have to "press LMB to climb ledge" in a passive 5 second animation, which gets frustrating already the second time you do it. And you have to do it all the time. For some strange reason it's almost completely abandoned after Act 1, as if testers realized it was utter shit, but it was too late to edit the entire level or something. Some mechanics are inoffensive, but puzzling in their inclusion, like sneaking sequences - nice basic minigame to mix things up those 3? times it's used, I guess, but wouldn't that time be better spent on, iono, implementing jumping on ledges? And then you have other fine additions, like QTE, which just screams "dated" like a finely aged milk, with a mold so old those bacterias easily invented the wheel already.
Potions are, save for maybe 2, totally useless. First of all they're extremely annoying to use, as you specifically have to sit down, meditate, watch every time the same animation of Geralt slowly drinking it, throwing it away, wiping sweat from his face... even though in 1 & 3 you could just drink it normally. Secondly, they last for 10 minutes or so (after animations 09:50) with the annoying clock ticking, so you better well time when you do it, or else half of it will be lost during "exploration", but why would you do that? There's just no incentive to even drink it, the effects are minuscule or straight up negative, with the retarded "trade-offs" like +10% extra damage, but -30% to total vitality. Why would you even gimp yourself for that, when already most enemies die in 4 hits? Ok, maybe it's better if you invest in Alchemy tree, but why would you do that too? The OP tree is Signs as usual (or sure feels like it), and Combat provides tangible benefits from the get go. Maybe the final "Berserk" adrenaline perks are something insane, but the game doesn't even explain what it does (and neither does it explain the Heliotrope sign, which feels good but is basically just a gimmick).
In order to highlight anything you need to press Z to pay respects with your medallion which has a few seconds cooldown for some strange reason. The game encourages you to do that to find "Places of Power", which were useful in TW1 & 3, but here I didn't even know what the buffs really did because they last 5 minutes, so by the time you encounter an enemy amidst all those winding roads you have to traverse, while jogging reeeally slow, half of that had already passed.
Said enemy will 99% be some useless fodder, buffs or not. Which brings me to the last point, of what I felt were bizarre difficulty spikes. Most of the time the enemies die in 3 hits and you can fight them blind, but occasionally you can encounter some tougher ones, like Endriagas swarming you if you're not paying attention. Fair enough. Then you have your first fight with Letho, which is something out of Dark Souls. Not extremely hard, but definitely feels out of place where you just spammed LPM like in some hack'n'slash. Then you more or less trudge along scripted sequences like with Vergen battlefield, or steamroll through countless harpies... until you fight what is, I believe, one of 2 mandatory fights in Act 3, that is, Saskia. If Letho was something Dark Souls-esque, then this is like one of TW3: Enhanced Edition's bullshit bosses, but twice as long. And if you invested in Combat, you're fucked. ~10 Minute fight of trial and error with tactics and learning all the patterns, with Saskia's head tracking you at all times so you do fuck-all damage up front, and have fun slurping those elixirs on every attempt.
I get pissed off just by thinking about that, and the answer is already quite long, so let's just leave it at that, even though those are not the only problems.
EDIT: Of course, you only know it's Saskia if you did the Iorveth path, or else you miss out on half the things relevant in this game, and the next one, like Filippa Eilhart, her owl form, and why is the dragon attacking in the first place - because otherwise you get no explanation. Like I said before, Vergen path is superior to Henselt path in almost every aspect. Quests are far more interesting, like succubus or lynching of Stennis, in contrast to that fucking relic hunting. Character selection is far more interesting, as exclusively in this path, you meet important ones like, once again, Eilhart, but also Saskia or Stennis you couldn't in Henselt path, but not vice versa, as you learn all you need about Sabrina Glevissig, Detmold, or Henselt anyway. You also hang out with your bros, bring Scoia'tael to its conclusion, and help good people, instead of working with repulsive degenerates like Detmold and helping that fat fuck with his curse and to win the battle, which just leaves bad taste in your mouth (arguably, this may be objectively more interesting). Maybe you miss out on Natalis and those 2 Temerian nobles investigation, and on Odrin, I guess? Even Roche is still your bro, in 2 & 3, and is better off if you joined Iorveth because Detmold is guaranteed to die that way.