Excellent and addictive! Beat the Dragon three times so far with a top score of 229. Just can't quite seem to get the order to clear the board.
It's RNG if you can clear the board. You need to conserve the healing scrolls for as long as possible to get the most value out of them, which means searching for the money chests and easy to break walls early on.
(This is just speculation on my part. Haven't played enough to know if this is exactly the case)