QCF: Papers, Please
oral choices in most games are easy. Save enough little sisters in Bioshock- you get the good ending, kill any and you're the worlds biggest monster. These choices are so ultimately binary that it's easy to even forget that they're questions of morality to begin with. Even when dealing with a complex issue, there's always a prompt telling you what kind of decision you made, regardless of your reasoning. "Yes and no" or "right and wrong" stick firmly into our heads to the point where we'll always know where our choices take us and what kind of end game they'll eventually lead us to.
However, Papers, Please doesn't play by those rules. In fact, it doesn't really play by any. There's no right or wrong here, only moral uncertainty and shades of horrific grays that lead to an experience which is devastatingly horrific, monotonous, and perplexing fun at the same time. Basically, it's one of the most interesting and creative video games you'll play all year.
Just don't expect to leave it feeling good about yourself.