The graphics and soud are old and unpolished, but you won't find a shinier story or gaming experience around.
Pros: Engaging story, strong characters, involving gameplay, FPS and RPG rolled into one, stealth/ action styles of play, non-linear, you can use your brain if you like.
Cons: By todays standards, the graphics are crap and some of the weapons seem to lack "punch", like the shotgun. Some dumb AI.
Why oh why haven't modern game learnt to be just as inventive and interesting as this? Deus Ex Machina: "God from the Machine".