The graphics are made by my graphics artist, using Adobe Illustrator and Photoshop. The game was in sandbox mode until today (my bad), so please do try again. I am having some issues with the facebook object integration, I've detailed them in another post (http://www.scirra.com/forum/forum_topics.asp?FID=45), so please take a look and let me know if it works for you.
The collisions are much better in the Construct 2 version, since the tool is so awesome :) The Windows Phone version is made with my own custom engine.