Speaking as another lit major, I think the best way to approach grading in this context is to acknowledge that it will be a) kind of super arbitrary and b) not to be taken very seriously.
On the contrary, I think everyone who managed to complete their game and submit it is a winner. As game devs we all know how easy it is to start something but how difficult it is to see it through to completion. Great job, everyone. Give yourselves a pat on the back. :)
