Metal Gear Solid clone suffers from same things.
Some parts are really easy simply because the bad guys cant shoot and others are impossible because the AI has super human senses and knows you are in the room/area even though you didnt move/push a button.
There are a few fun aspects here like in metal gear solid like sneaking past a room with 6 guards and silently killing the one at the end, etc...but really this plays like a MGS clone.
With that said it really does a lot of things better and more originally, if i was going to replay either THIS or MGS i would pick this. I'm not ever going to do that but im just trying to say this game did a lot of things well despite being boring/non-creative.