I rather enjoyed the detail of the game, though, the repetition of some cookie-cutter assets becomes noticeable after awhile.
The weapons modding mechanic, was excellent and I like how it's staggered where you can change the mods on the 3 weapons you're allowed to carry at any time, and can craft certain items on the fly, but, other items and weapons maintenance like cleaning can't be crafted without a weapons workbench.
The only thing I had a minor issue with regarding that is the weapons selection load-out could only be changed at the train crafting station workbench. You select weapons 1, 2, and 3, and you can swap out 1, 2, and 3 in the field if you find and kill someone with something you decide you want to use more instead, but, only if you find it. It would have been nice if you could choose from all of your weapons at any weapons workbench. I recognize that as unrealistic but, it would have been a little more convenient.
My biggest problem with the game was the old "Now we take all your weapons away" level.
I've complained about that trope in the game industry before and find it annoying AF. You collect a bunch of things throughout a game, and then, suddenly, you're forced to give it all up, and gimp by without for ... reasons. Ugh.
The stealth system was fun. If you're noticed after attacking someone, that's it; they're on alert, and they don't forget about you after X amount of time, like all those guys in Skyrim that could be oblivious about an arrow sticking out of their head.
No, once the enemy knows you're there, they're on alert, and stay that way for that location.
It would, however, have been nice if they'd have included a pick-up body mechanic to allow for hiding dropped enemies from roaming patrols. That's not a big issue, but, it'd've been a nice feature.
The game was also much shorter than I would have liked. If you're something of a completionist given to spending lots of time on doing, finding, and seeing all the thingses, and it's a game on rails that doesn't have branching stories, or multiple endings, then, once you've done one play through, there's not much incentive to play the game again, ever ... unless you just want to repeat yourself.
Over all, it's a beautiful game with fantastic voice acting, stellar cut scenes, an interesting story, wonderful details, and fun weapons system. It's, however, a shorter game than I like and doesn't have a high replay value.