I finished Bioshock early last week and managed to get the good ending because I’m a fine and moral person. That or maybe because I never felt it necessary to follow the so-called “evil” route because I felt that the game sabotaged its own moral decisions.
Let me backtrack a bit first. In Bioshock‘s world there are these little girls that wander around the city in search of the genetic resource “ADAM”. You, as the player, need ADAM to improve yourself so that you can progress through the game and the only way to get it is by capturing these “little sisters”. At that point you are given a choice: do you kill her and get the maximum amount of ADAM or do you rescue her and get a smaller amount? From a pure gameplay perspective the former option is the unequivocal best choice.
Which is precisely why the carriers of ADAM aren’t giant slugs. Giant slugs we can harvest for all their worth. Little girls, even twisted ones, make that choice an uncomfortable one. You’re more inclined to want to save them even at the expense of a resource that you need. Unfortunately, the game undermines this balance by rewarding you for making the “right” decision. For every few girls you save you are sent a message thanking you and a bunch of “gifts” including ammo, maybe a new plasmid and some ADAM.
It sabotages the whole moral decision. The ADAM you get from these rewards nullifies any “resource or conscience” decisions since, in the end, you will always have a near equal amount of resources (though this process is marginally slower, but that difference is negligible) so there’s no advantage to playing the immoral choice. Gameplay wise, you are no worse off taking the moral route and because of it there’s little reason to take the evil route, save for curiosity. It’s a little disappointing.