It's Not "Just Another Shooter" Just Because You Didn't Get It
Check the net. Read interviews with chief designer/writer Ken Levine. Bioshock really is that clever; it really was designed to be a story with many levels of meaning -- BUT it was also intentionally designed so that, if all someone wants to do is play it as IF it were "just another shooter", you can do that. You can basically ignore all the ideas, and pretty much the entire story, and just play along, blasting pretty much anything that moves, like the typical cliche, cheese-eating frag monkey.
But just because you decide to play BIoshock on autopilot, doesn't mean it's as simplistic as you choose to make it.
Here's a minor example, and it's not even a spoiler. There's a small graveyard in one part of the city of Rapture, and in it, you'll find tombstones with the names John Maynard Keynes and Adam Smith on them. This is a very subtle, sly joke that relates directly to some of the themes and ideas in Bioshock's story. Go ahead, go look up the names on Wikipedia if you don't know them. I'll wait ...
Back? Good. Here's the thing: the tombstones are nothing more than a throwaway joke, but they still relate to the game's story. A game that's "just another shooter" doesn't have elements like this, because the designers don't even think hard enough about the story to put them in.
So what? You don't care? Fine. You don't *have* to care. That's the whole point I was making above. Bioshock's story depth is designed to be both subtle and optional. It's meant to be an entertaining game, first and foremost, so you're given a choice as to how much you want to put into the game, and how much you want to take away from it.
But just because someone doesn't get all of what's going on behind Bioshock's story -- or doesn't care to get it -- doesn't mean that detail, that level of thought, and that story depth aren't there to be found.
Bioshock is that rarest of things: an entertaining story that simultaneously talks (symbolically) about the human condition. It uses the past to talk about the present, and about human nature. One of the many themes, for example, concerns the dangers of people who get so in love with their own particular point of view, that they can't stand the idea that others might not see things as they do.
Sound like a few political parties you know? A few religions? A few philosophers? A few friends?
Maybe even a few Gamespot reviewers who insist that Bioshock is "just another shooter" merely because that's all **they** cared to see in it? ...
There's much more to Bioshock than just the standard run and gun action. The story is subtle, but it's through-going and intentional.
Bioshock's background themes and ideas are optional, but they're there for those who want them, who want that story aspect.
Just take a look.