I think the overall transfer to 8-bit was great... but I feel like this is missing something, as in it doesn't sound full enough. You definitely filled up the space for the melodies really well, I just thought it could be better if it had some sort of drum part or bass part.
Like I said, melody execution is great and retains the epicness of the original, but there's no low. The original song has this really epic bass part (which sounds like cellos or something) and a fairly simple drum part. Other than that, nice job!