"This essay is about an interesting and important topic."
That does not mean you, personally, have anything interesting or important to say about it.
"There are some promising ideas here..."
Too bad they don't deliver on that promise.
"... especially in the third paragraph on page 6."
That paragraph was almost coherent; the rest of the essay was ten pages of mush.
"This is certainly an original interpretation, but it needs more supporting evidence from the text."
Wow, that's the first time I've ever heard anyone argue that Macbeth is secretly gay and he kills Duncan because he can't verbalize his love for him. I hope it is the last.
"Proofread carefully; the many sentence-level errors in the paper distract the reader from the quality of your ideas."
Note that I'm not actually saying the quality of your ideas is GOOD, just that it exists.
"You have several well-chosen quotations and examples from the text, but this essay needs a clearer central argument."
I've already freaking READ Beowulf, thankyouverymuch. Please SAY something about it already.
"You have clearly been paying attention during class discussion, but this essay would benefit from closer attention to the text itself."
The fact that you think Titus is friends with a character named "Ronicus" kind of tipped me off that you haven't done the reading.