Not only does it convey atmosphere and story masterfully, it also implements RPG mechanics organically.
The World
Most of System Shock 2 takes place on a massive space shuttle dubbed the Rickenbacker. While you might assume that this would result in the game's setting feeling repetitive and perhaps even bleak, the game actually delivers quite a different result. There is enough variation in design and the color palette from room to room and floor to floor that the game never feels repetitive or dull. Part of the game is not on the Rickenbacker at all and the same goes for these parts of the game: the setting changes enough to keep you interested. The most consistent factor in SS2's setting is that it constantly and effectively delivers terrific atmosphere, thanks to the artistic direction and even more so, the sound (but I'll get into that later). It's hard to look at this game and pick out one little piece that creates a strong atmosphere, because the atmosphere is as strong as it is due to all of these pieces coming together effectively. Every little item, significant or not, manages to have an effect on you, and that's a beautiful thing to have in a game.
The Story
So much has happened on the Rickenbacker for the player to discover that it really does make for an enticing adventure. The story progresses through audio diaries which are absolutely essential to the plot and objectives. Much like SS2's spiritual successor, Bioshock, the player is allowed to uncover the mysteries of a strange, unfamiliar world one secret at a time. In order to keep this review spoiler free, but at the same time emphasize the importance of the main villain in the game I am forced to be vague and undescriptive. The villain in SS2 is the best villain to ever grace a game whether it be a computer game or a console game. This villain will mock you, undermine you, and straight out insult you, and that was one of the key factors that kept me playing... okay, kept me ADDICTED.
Sound and Visuals
System Shock 2, just like in all other areas, delivers here as well. While the graphics are obviously outdated (this a 90's game... duh) the artistic direction and dark color palette manage to make the game beautiful in it's own way. The sounds in System Shock 2, save for some of the misplaced techno music, are absolutely spine chilling. The audio logs sound like real accounts of what was happening aboard the Rickenbacker, even in ones where the voice acting could be better. Somehow, the game manages to age well, even in these areas, the outdated graphics never detract from the experience in any way.
Gameplay
For the most part, SS2's gameplay is that of a standard shooter. Like Bioshock, you have special abilities in one hand, and guns and melee in the other. What really makes gameplay special is that the RPG elements and gameplay customizations are the best that any FPS has ever seen. Games like Fallout 3 and Mass Effect, while great, cannot touch the RPG elements of SS2 with a ten foot pole. Combine fantastic RPG elements with the need to constantly conserve health and ammo and you've got yourself one of the most unique gaming experiences ever, or a sci-fi/survival horror/FPSRPG. Combining those styles of gaming is not an easy thing to do, but Irrational manages to make the combination feel natural. You might find yourself wondering why no other sci-fi/survival horror/FPSRPG games exist after playing this.
It's no wonder why System Shock 2 has been regarded as a classic by so many. It's been the influence of games like Dead Space, Fallout 3, and even Deus Ex. System Shock 2 will be forever held in high regard, thanks to its overall magnificent quality as a game and as an experience.
The World : 9.3
The Story : 9.5
Sounds : 9.8
Visuals : 9.2 (artistic, not graphics)
Gameplay : 10
ACTUAL overall score : 9.7