I tried to get into the game 4-5 times, but its plain too boring. And yes, i enjoy patient games as well, but this is just not entertaining. You cant properly attack if discovered and cant run away either. The parkour is unintuitive and pourly executed. You will very often drop from ledges, miss a jump or simply not know whether you can make it or not, because there is 0 indication as to whether something is too far away or not.
The levels claustrophobic and difficult to navigate, let alone memorize. First missions consist of multiple levels, utterly useless and fake paths that lead nowhere, nor are needed on any occasion and i have yet to find how to lunge onto someone from a higher position. Right now you could stand behind someone, but if he is like 5cm higher or lower, you cant execute him.
Looking through stuff you can acquire with skillpoints, there is nothing worth playing for. No cool, extra abilities, no game-changing mechanics. If you release a game that attempts to combine goblins, ass-creed and dishonored, but have only a stinking goblin who can puke out an another stinking goblin, you get Styx. And its bad.