Algodoo

I'm testing control schemes for an upcoming hovercraft and this is the best I've come up with.

It's mousecontrolled, keep the mouse inside the big circle to control it. If you move the mouse outside the control circle the box in it will turn red and you're not affecting the hovercraft anymore.

Tell me what you think and what could be better.
I don't care much about the handeling of the craft yet, but if you find major flaws feel free to share.

Also if you like to use this for something feel free.