System Shock 2 is awesome, but the RPG kinda makes the gameplay tough, sometimes annoying.
In start of the game, you set what type of marine you want to be, choosing the skills that you think that you would most fit best in the game. But if you want to go the easy way out, you have to choose the Navy. The skill of hacking. There is 3 main skills you choose before the game actually starts. 1.) Guns 2.) Will(?) 3.) Hacking. Once you made your primary skill, you cannot go back, and then it would make it harder for you in the other skills you did not choose to master.
During the game:
The ship got outta control and you are practically the only human left alive on board. You have to work your way through mazes, finding keys and key codes, to get through the next destination; which can be frustrating at times, because you have to search all around for a "key" of some kind to get through the next door. Combat makes it irritating in the game. If your master of guns, but not repairing guns, then you will have a rough time, getting past the zombies and creatures that try to kill you along the game. And using stealth is very hard in the game, because it doesn't give you an indicator if your detected or not. The pure RPG in System Shock 2 keeps you from making your life any easier, and you wish sometimes that the RPG in the game, will get outta the way sometimes. Overall, the game is pretty much similar to Doom 3, but added RPG style to it that makes it hard.
Now the RPG style in System Shock 2 isn't all bad, because you can pick up anything and use it for something in the game that you never know you might ever use it.