It wasn't a bad start. A few suggestions though;
The game never exited for me, just kept going even after I got all the rectangles as well if you lost when you reached a negative score, you might want to check your exit statement. Also I noticed you used watdotcolor, which I would suggest using coordinates instead for the walls and paddle at lest, since every now and then apiece would disappear when making contact with the ball. (I didn't actually look through your code, these are just suggestions from the game itself.)
Some music may make it livelier, and it would have been good if u bundled the images and the file together in a .zip or .rar form so that it's not necessary to download three different items.
Other then that I thought it was a good start.
