Ahaha I uploaded a version of Viva La Vida on my Youtube the day! This was a really great idea and it flowed surprisingly well!
My only criticism is to really pay attention to detail. A capella recordings like this require so many different layers of vocals. If on each layer you have a part where you're off-beat or out of pitch the tiniest bit, individually it's no big deal. Of course, if each part has these flaws, they all build up and it can sound a little messy ^0^ really practice on perfecting each and every part so that you can really reach maximum potential.
I really enjoyed this~!