Algodoo

I have built a rotary collision engine- one that does not use pistons, but instead spinning discs. This causes a major boost in performance and reliability.

I also included a car powered by this engine. It goes slow, yes, but that is because I geared it down a lot.

I also included a version that is also a density engine- this one will blast itself out into the stratosphere really quick without any source of propulsion other than itself.

I also included what I believe is the Final Incarnation of my density engine- it is entirely collision-based now and has enough controls to function as its own little helicopter.