I would definitely recommend this game to any stealth game fans.
I was interested in this game when it first came out but only recently got around to playing it and didn't know what to expect anymore but thoroughly enjoyed my experience. It felt like a cross between Thief and Assassin's Creed for me with some of the mechanics and was great fun to play.

Since this is a review, and I've seen some negative reviews addressing things I did not personally experience, I would first point out that your overall enjoyment of this game would depend largely on your playstyle and tolerance of minor glitches. Summary of main points I feel are important to consider below (some of them are a bit long, but I want to share my thoughts on my own experience in case it helps someone :) ):

Story related stuff:
I thought the story was great and interesting. It is very linear but was not consistently predictable like many stories are these days and the overall feel was in character with the protagonist even as his motivations and goals may change. The dialogue was fun to listen to and the voice acting was good. The world also has a nice feel to it and while there is no lore to find which this game might have benefited from it's still nice to explore and look at and listen to NPC conversations as you sneak around.

Graphics and visuals:
I found the graphics to be very pleasant especially for their age. Sometimes the lip syncing of the characters in cut scenes was briefly a tiny bit off which was a little bit distracting and occasionally there's some clipping when climbing or something but it wasn't enough to ruin my enjoyment.

Level Design:
This game has no overworld to explore, and is just a mission to mission type game.
Judging by a couple of the reviews, some people do not agree, but I thought the level design was very good. Minor spoiler: You come back to some of the levels later in the game, and this might seem repetitive for some people, but I found it didn't feel reused, but fit well with the story of the game and with established locations in the world, especially as strategies upon revisiting areas must change as it's not just a copied level with enemy patterns etc.
Overall, there are many different paths and shortcuts, there is no single path or best path, it all depends on your playstyle and in one level you could wander around exploring and take the same path back and forth to certain areas, take a number of different available routes or make use of different tools/mechanics at your disposal to avoid being seen. I found the levels fun to explore and the different techniques fun to experiment with. What could have improved it more is if there was more incentive to explore, such as additional collectibles with lore or something like that, but it was still fun with the existing collectibles and resource stashes.

Gameplay:
The combat is very one dimensional, simple and not too great. That said, I engaged in combat exactly twice the entire game when it was part of the story and tutorial (not including achievements). This game is primarily a stealth game and it makes logical sense that the main character would not be good in a proper fight/confrontation. So probably not a game for you if you're more interested in open combat.
It feels like the intended way to play this game is by stealth and here is where the game really shines in my opinion. There is no one way to do things. It's possible to sneak by enemies with various different mechanics/skills/paths completely without killing them. On the other hand there are also a few different ways to assassinate enemies to clear a path which can be either done strategically or by murdering everyone. I did go on a couple of killing sprees and killed enemies because it felt appropriate for the stories of those levels, but these particular levels made me glad of my usual approach, as systematically killing enemies then just running through a level removed a lot of the satisfaction of having figured out the best way to approach a situation and come out of it completely undetected (including in my brain, in the future where missing people will still be discovered ;P). Of course my own perspective here is probably coloured by my own imagination/role play and my additional interest in puzzles so make of that what you will ;) Your personal satisfaction might be from assassinating all the enemies ;)

One other thing to note is the game includes certain mechanics which make the game more realistic but can also make it more difficult for some people or certain styles of gameplay. For example, once alerted by something intended to draw a guard away from their post for a collectible, they will be more aware and possibly harder to sneak past if you need to get by them again.

Difficulty:
Personally I started on normal for the tutorial and a couple of achievements that can't be done on higher difficulties, but I found the best experience to be Goblin difficulty as everything else simply made things too easy and I'm not someone who plays games on highest difficulties often.
However, obviously pick the difficulty that best aligns with what provides you enjoyment, but the reason I felt a higher difficulty was better here as you're more likely to use your various tools and mechanics to progress without being noticed, or you are forced to think more strategically about different routes and approaches to specific paths or collectibles. This, for me, was one of the most enjoyable aspects of the game and it was very satisfying to grab a token from a difficult location after strategising the best approach and still conserving resources.

Issues:
The one main technical issue I had with this game was that there was no audio in the intro cutscene, but menu and game audio was fine. It was a bit weird, but I fixed it by changing my audio settings to a higher sample rate (I think it was 96000 Hz). This issue only occurred when using a speaker, not with headset.

Some other people have mentioned sometimes some things change after a save/reload. This wasn't a huge issue for me because I never had enemy bodies randomly laying around, but even if that were the case, I would suggest to make use of the numerous saveslots available and rotate through a few saves for a level. I used a system of 4 per mission, saving over the oldest every new save. I never hit any limit and never personally had to go back to anything other than my latest save except by choice, but useful if you do encounter any glitches.
The main ones I saw myself when reloading a save was enemies could be at a different point in their patrol or certain items were reset. At most this just meant I needed to wait a bit longer so was nothing more than a minor inconvenience for me. I can see how this might sometimes affect enemy bodies, so if that is your playstyle, more frequent saving in different slots could help :)

Suggestions:
Lastly, there are a couple of things the game could have done better and had I known these things in advance it would have saved me some time and frustration.
1) Some things cannot be accessed/done right away so if you can't find a way, there might not be one. (I have mixed feelings about this, I like that it's there consistently, but could be clearer some things aren't accessible right away)
2) Worth checking the controls in the control menu after the tutorial mission as there is one thing the game doesn't mention you can do and one other which isn't clear unless you pay attention to the icons when using skills.
3) I'd suggest taking a screenshot or picture of the tooltips when a new mechanic is introduced as sometimes it disappears too fast and you can't always get it back.

Overall I thoroughly enjoyed this game and hope this helps someone decide if this is a game for you to try or not if you're on the fence :)