This is a quick build for a twenty piece contest. To shoot something all you do is turn the "wheel" on the side, the technic piece sticking out hits the ground and causes a brick to fly out around eight feet! I guess thats all for now.
I gave this a 13/15. I love the idea of a catapult. This is well built, but it also looks a lot like what was made for set 8038 Battle of Endor. That could just be inspiration, so I didn't want to attack you too much. Nice entry.