The self-aggrandisement shown by you in the forums and here in the description have led me to give you a review. Just be forewarned, it's scathingly honest.
There's nothing new that you added to this theme. All you did was an 8-bit version of this theme, which I'm more than certain has been attempted before, and better, on OCRemix. A cover that blows my mind would make it truly new, give it a spin that only you could do. 8-bit stuff has been attempted by so many people, and yet... 8-bit and voices, or merely a capella? Now that hasn't been done yet. Everything is exactly like the original, too, in terms of chord structure and how the piece is laid out. Which makes me wonder if you transcribed this by ear, looked at sheet music, or replaced the instruments in a MIDI of this thing with your 8-bit sounds. Option number 3 (the MIDI one) is not allowed by Newgrounds rules, anyway.
Good covers would switch the chords and slides up. They would perhaps change the genre, give us something unexpected. They would take people by surprise. This one doesn't.