I disagree. The 4th dimension may not be what the Magic Cube simulates, that's just a theory.
But 4D does exist. I'm no expert, but the 4th dimension is used in Calculus all the time and is represented by colors (ie. temperature, wind direction, etc.). Another theory is often that it is time, which certainly exists. Another theory is the in-out, forward-backward, etc.-etc. that the two games use. There's probably a zillion more.
Anyway, it's all in fun
. The guy who made the maze game talks about how he tries to "see" the fourth dimension in everyday life and can't quite get it. It's nuts, but it's fun.