Algodoo

This is my first real creation, I've made tank-like things and simple cars, but this is the first one to actually take more than 10 minutes to build. The locking mechanism actually took a good half hour just to find the right balance between motor power and spring strength. Basically you draw the arm back and into the spinning gear, locking it underneath one of the arms. You then load the catapult with a shot from the ammo wagon, then press Enter to launch the arm. Left and Right arrow keys move the catapult.

This isn't so much a "Look what I made!!!" post as a "What can I improve/remove/add?" post. Very new to Phun so go easy.