Playing as a character is probably the point of the simulation, significant cheat codes quickly become boring so they likely would be living as an ordinary person and so difficult to distinguish. Their knowledge and skill set might even be limited to simulation appropriate levels. The scale of the simulation is important too, if it is not limited to just the Earth but simulates the entire galaxy or universe then it is likely we are too mundane of a locality to be visited and are actually just living our lives as background scenery. Or perhaps most of our history and evolution was ticked away theoretically and we are only actually simulated when we are visited. It is hard to believe dinosaurs lived 365 days a year, all that time on their hands, all those long summer afternoons to idle through.