Algodoo

Why use thrusters? You can move any object by setting up its "controller". Much simpler! Right click on the object that you want to control with keys, then left click on "controller". You can then adjust many parameters such as acceleration, and you can select which keys will give movement. Try it!

I thought that controller only used Mirror/Delete. I'll check, and if I can, I'll Update it, but I think thrusters are pretty good for the job..

Okay, so it works better, but I like changing the speed individualy, so it is easier to make it faster to go up/down.