I'm an Avatar in Someone's Simulation Game?

Philosopher Nick Bostrum has proposed a theory of simulation. He says that in the future, our descendants are running a simulation of us their ancestors. In laymen's terms, or at least in gamer terms, the simulation theory goes like this. The computing power in the future would be big enough and sophisticated enough that the simulated universe would be indistinguishable from base reality. But very simply, would they have free will? And what if i am really an avatar in some one else's simulation game? Look, who am i?