Styx: Master of Shadows is a stealth game where you play as goblin with magical powers to assist him on his journey, like cloning and making himself invisible. The game is played from a third-person view, similar to Hitman games. I would describe this game as a "hardcore stealth" game, since stealth is the only important thing here. There is combat, but it's just timing hits to parry your enemies, serving as a last resort. You can only fight 1 enemy at a time, making stealth the ideal way.
Levels are wide and open, with many enemies. The better you perform in a level and by completing sidequests, you will get more points to upgrade Styx's skills. However, you can only upgrade skills in your hideout. There are 4 "insignias", or requirements to get points: undetected, no kills, finish under allocated time, and collect 10 tokens per stage. It will be really difficult because of the way the game is, but luckily you can do each separately.
As I mentioned before, S:MoS is hard, probably the hardest stealth game I ever played, even on lowest difficulty. Enemies are very perceptive, and they are rarely alone. Navigation is hard too, with a near-useless map that only shows the whole area, but not where we are. I'm gonna be honest, it's more frustrating than fun lots of times. Lastly, I dislike the fact that you cannot just knockout enemies, it's either loud kill, silent slow kill, or abandon them. It would be better if the silent kill part is replaced with knockout.
Despite its flaws, Styx: Master of Shadows is still pretty okay for a stealth game, but don't keep your expectations too high. It would be a lot better if the game was easier, as it would not deter the more casual players or makes them resort to cheats. There are many better stealth games out there, but if you have done most like I did, this game is still worth a try.