Definitely an interesting idea.
You could blow through your deck very fast playing earth towers and quicksands:
Turn 1:
photon, cremation, this x 2, earth tower x 2, quicksand -> draw 4! -> earth tower x 3, quicksand -> draw 6!....
Although this would have problems with reliability, I think it demonstrates that it might be a touch too powerful. It seems like you either need to make it not stack or limit it to once per turn?