Actually, an unspeakably crappy simulation may be indistinguishable from the real thing if it doesn't "fight fair". Just have the simulation delete any thought

Actually, an unspeakably crappy simulation may be indistinguishable from the real thing if it doesn't "fight fair". Just have the simulation delete any thoughts by the participant(s) that they have convincingly observed anything amiss. The simulation might not quite fit in 640KB, but we might be rather disturbed at just how trivial a sneaky simulation of our world would be.