Overall Positives: Wow, everyone's vocals were great. It was a beautiful cover.
Timing: good. Nothing to complain about.
Volume: Some of the volumes sound not quite the same, but I'll really get into why in the next section.
Overall Sound: In this song, you can really hear the difference in mic quality. Jenna and Valentine 's mics (though sometimes Valentine's sounds just fine) are a bit tinny so maybe a little fiddling with PE could have helped. Naniko and Molly's mics are pretty clear. Tomo is bit muffled, but Celia is really muffled. Those could have been helped by either a high pass filter or some playing with PE. Because of these kind of mic differences, while they may visual be the same volume, by ear they're different due to the different interferences of different frequencies.
You know how when 2 people sing together it gets louder? that's constructive interference. Well, if you can imagine while 2 volumes add up together to make a loud volume, the volume of the frequency you want may might be not high enough, but because the other frequencies that are garbage are loud, it adds up to a big wave form. PE or Parametric Equalizer is a great tool because it allows you to take your sound, and then select for the frequencies (usually described as Hz) that you want. Voices tend to be in the higher frequency range, so when it's muffled, that means a lot of your extra volume is probably caused by lower frequency noise, so you can kind of weed that out by lowering the volume of your low freq stuff and increasing the volume of your high stuff. However the tinny as well as hissy sounds are in the high high frequencies so you can turn those down to help.
I don't know if this make sense. It makes more sense if I had a blackboard. Remember trig for those people who had high school? Sound waves are no more than complicated sine and cosine waves. I'll shut up now on my nerdy talk.
Overall Vocals: Everyone was great... on pitch with energy. It was so pretty *-*
Other: I apologize for my long science lecture in the middle there.
I need to learn something about vocals to comment... but I really don't know much to help.