Delightful!

I twitch when I see spelling, punctuation or grammatical issues. This game not only permits a guilty indulgence in correcting others errors but also delivers a splash of humility: it improves my own wordsmith skills each time I fail to flunk a student.
This is a fun game that would make a good gift from a parent or teacher to a student: A+!

Llyndwyn about The Grading Game, v1.0