This is really cool, and playing with it made me smile. I wish it had two things:

1) A way to delete objects that you placed by accident. (perhaps there is a way to do this which I couldn't find). I keep going back a page and losing everything because I press the delete button.

2) A way to label layers, with generated descriptions of what the layer is. i.e. Here is a new layer called a "heart". A heart is two circles and one square. A "valentines day picture" is two hearts. Likewise, a "tree" is a rectangle, with another a rotated "tree" touching one end of the rectangle. I can imagine this being a great way to explain programming concepts in a visual way, and giving people the vocabulary to talk about them.

As for my artistic abilities... http://cl.ly/251m2k0z1Z0z142r3S42