"Given the fact that we could potentially be the directors of our own
mini-universe, in video games like the Sims how do we know if its
inhabitants are self aware? If they aren't currently self aware, at
which point would we be able theoretically to say that they could
wonder about their own existence?"
You first need to define "self aware", and the quality of your Sim. Why could any future civilization not apply a "Turing Test", and a "mirror test", a measure of self-awareness, to a Sim? This question reminds me of the classic "brain in a vat" problem:
Why must the referents of our terms be accessible to us in experience?
One cannot, for example, have experience of other people's private
states of consciousness; does this imply that one cannot meaningfully
ascribe mental states to others? (Wikipedia)
Someone might argue that if there is no empirical evidence to appeal to in order to establish whether we are, or there are, brains in a computer model of the world that can simulate human conscience, then the hypothesis is metaphysical. Many philosophers would maintain that such metaphysical possibilities do not amount to pragmatic cases of doubt: At present, it is physically impossible to make a computer model of the world that can simulate human cognition and replicate the qualitative phenomenology of a human conscience. Nevertheless, one should hesitate before making possibility claims when it comes to future technology. As films like the Matrix and even the Truman Show indicate, the idea of living in a simulated world indistinguishable from the real one is likely to continue to fascinate the human mind.
Internet Encyclopedia of Philosophy