I think the idea is really cool, grading exams but with a twist of luck makes for a fun premise! I think this could be a smoother experience if 1) There were less questions on each test 2) More variety of subjects for the tests, while being more specific. For example as someone who has studied art I still couldn't manage the art history test here because I don't know the specific dates someone painted something off the top of my head, but I was able to identify the paintings. So a more fun version of it might have been if it focused on simply identifying them. Then you could have similar tests on different kinds of literature, or science, etc that are specialized in their own ways. Those are just my personal thoughts though, overall it could be communicated more clearly but the concept is good.