Really fun game! But I'd like to report some bugs in the demo (playing the web demo on my android using firefox):
1) I play one level, go to she shop, and as the letters for the next level drops, it becomes very laggy and crashes. I'm basically playing one level at a time.
2) When continuing the game after the crash, I was able to purchase runes and wands, which I don't think I was supposed to be able in the demo.