This is an interesting theory, one that each of the evaluation criteria could be applied to. If you wanted to apply conceptual clarity, you should reflect on whether or not the idea is clear and why. This would involve asking specific questions for any parts of the theory that comes across as unclear. If you wanted to apply experimental confirmation, consider if this theory opposes any facts that are proven by human life experience. This is different than proving a scientific fact through experimentation. Instead, you should consider if there are any parts of an almost universal human experience that complicate or contradict this theory. If you wanted to apply rational coherence, make sure that the theory does not contradict itself.
Let’s say you decided to focus on evaluating the implications of this theory for ethics and daily living. First, consider the various ways the world would change if Americans had their brains hijacked. Then, narrow down your thinking and consider how this would change ethics in American society. For instance, “the Gamers” would now be in control of Americans’ thoughts, which would mean that the conception of morality in the Gamers’ society would now be the approach to morality in American society. This may change the way Americans view right and wrong, which would change what is considered a morally acceptable action and what is not.