Nice game! :D
No, but seriously. Great art and the gameplay is great too, keep up the great work!
Edit: Thought I should come back to give some explanation for what had happend in the video and some feedback.
It just looks like you can pretty much let every witch destroy herself by upgrading the expansion potion a lot. This also gets a lot worse if you keep on going.
Also I'd really love to get a gallery where you can see all the transformations you've already seen