I would hypothesize wildly that younger students might respond well to this for the same reason that young children prefer the Kraft macaroni in the shapes of c

I would hypothesize wildly that younger students might respond well to this for the same reason that young children prefer the Kraft macaroni in the shapes of cartoon characters—it's a kind of association, "This is fun because it is like the video games I play!" I suspect both that a. it would become less effective as the students aged, especially towards the end of primary/elementary school, where students might see it as a kind of trick, and b. it would become far less effective if it became the standard way of running a school, because it's no longer "like a video game," it is "like a school." Which all is to say that it's not the experience points that are improving the experiences, it's the mental association with video games. I'd be happy to be proved wrong, though, and I don't think that the experiments with this shouldn't be done—I'm just skeptical.