This game is not an immersive sim, partially because of it being third person and the game having many arbitrary scripted sequences. Despite that, it is a very good game in my opinion. I have 100+ hours played in this game and I don't remember most of them, it's a very replayable game.
This is the best single-player game ever made in the past 15 years, in my opinion. It abandons nearly all fantasy elements (with the exception of some unrealistic potions and witchcraft-y side mission(s)) with a focus on realism and historical accuracy. I'm not a history buff or a huge fan of the time period of which the game is set in (circa 1400AD) but I still appreciated it. Combat is kinda ass against multiple enemies and is super easy to cheese when you learn master strikes but is still enjoyable and requires skill to master. Hardcore mode makes exploring so much more enjoyable, it has the best forests I've ever seen in a game and it is a blast to get lost and doing things like looking for landmarks and using the Sun to identify directions. It will take you 5x as long to beat the game on hardcore but it's so wonderful. Play it if you can.
One of my favorite games. This game was clearly made with immersion and believability in mind when designing the mechanics and world. As far as I know, there haven't been any open world crime games that have gotten close to this game in that regard. Sue me but I like the gun-play. The harsh recoil on the Tommy-Gun makes it feel very powerful along with the other firearms in the game. I also like how your bullets don't just spawn on the crosshair but actually come out of the barrel of your gun, which is why you often get bullets hitting a surface that is close to you rather than where your crosshair is pointing.
In my opinion, this is the best immersive sim ever made. I'm not gonna be some weird anarcho-whateverist and pretend that this game is a "redpill" like others do, but the story is pretty good. (Is your entire world philosophy based off of a fictional video game story? Yikes). There are a lot of hidden areas and opportunities that are in the levels with incredibly non-linear level design. Good game, I don't recommend playing GMDX or Deus Ex: Revision as those change too much and ruin some parts of the game.
If there were AAA games in the first person parkour genre that weren't part of the Mirror's Edge series, Mirror's Edge would be slated as a mediocre, bland, game. I don't think it's bad but holy cow, the combat sure is. Same with many levels in the game. Who would've thought that having huge parts of the game just essentially being quicktime events would be unfun?!?!
I've somehow played through this game twice despite me not liking it very much, at all. My theory is that the game's good graphics and relatively exciting scenarios in (most) of the missions keep me just barely stuck in. I find it ironic that I finished this game over a period of a few weeks but still have a very hard time finishing actually good games, like FEAR, Deus Ex (I played through the game to about France twice but only beat it on my third lengthy attempt of playing it, haha), and the first two STALKER games.
One of the few comparisons I can make of this game to other games is if it is Assassin's Creed but set in modern times and instead of being an assassin that uses a blade, it is a hacker who has guns. Kinda a weird comparison but it draws many similarities, the towers in Assassin's Creed are functionally similar to the CtOS centers around the map. The cover system is similar, they're similar in that they both have pretty good graphics but just feel soulless in terms of design. There is very little that is genuinely interesting in Watch Dogs. The story doesn't make you think at all. Sure, Aidan is ethically grey in some areas but all of his attacks in the story were a form of self defense. The bad guys in the story are completely one dimensional, they're 100% evil, and nothing good comes from them. You don't ethically question who's in the right here because it's obviously Aidan and that's true for the entire storyline. It is so boring and cookie-cutter that it makes me so much angrier than just an outright bad game that at least tried to bring something new to the table.
Driving the cars in-game feels okay though definitely not as good as GTA 4's driving (Everybody who says that the car driving in that game was bad is an idiot, pass it on. The driving just takes skill to master.) It feels very floaty in how you drive, and just, off, in a way that's hard to describe.