This is a really nice and polished game. The game looks great. The vision cones work well. You have nice indicators for enemy states. Really well done.
There is only one, unfortunately really big problem. There is no way to kill/take out an enemy without getting into a gun fight. This really defeats the purpose of a stealth game. A good way to solve this might be to make enemies 1 hit kills if you shoot them from the back.
The problem might not have been as big, if you could just evade most of the enemies. Unfortunately, it's necessary to kill the guy with the briefcase. He has killed me multiple times, even when I approach him from behind and get the first shot off. Due to this, I was not able to complete the tutorial, nor the first level.
It's really disappointing that this problem exist, as it basically makes the game unplayably punishing for me, while I think it would be a really great game otherwise. If possible, you could put a link in your game's description with a fix for this? Because I would love to play the full game.
I'd really appreciate it if you would have a look at my game as well, and be sure to download the smaller version :D
Edit: I tried putting the damage settings as easy as possible, but it's still too punishing for me.