As promised I wanted to tell you what I think about your demo: It certainly shows that you are going in the right direction, it already has the most important stuff working (music is running, collisions & controls & scentransitions are working) and I guess it will be even better when you release the full game that has a winning condition and more levels etc.
I think you could improve a bit on the artwork, it seems that it was collected from different sources.
I could imagine it could work good for you game if you take inkscape (it's free,
http://www.inkscape.org) and let you inspire by some tutorials:
http://2dgameartforprogrammers.blogspot.de/ This might not exactly be the stuff you need for your game, but if you look at the tutorials you might get the idea how to transfer this to create the game art you want.