A Willing Suspension of Disbelief is a must for almost any work of fiction. There are certain elements of story or gameplay where realism would simply make a work tedious, difficult, or confusing for the audience. Thus there are ways in which works will be blatantly, unabashedly unrealistic, and nobody really minds. See the Rule of Cool. It's possible for these to become unacceptable, when the abstraction gets in the way of enjoying the work. On the flip side, it's possible to get so accustomed to a particular break from reality that people stop realizing it's unrealistic.