Algodoo

A funny idea I've had for a while now. Not what I'd call a good idea IRL applications, but it works nonetheless.
Nice thing is it's technically unstallable, and repeats the strength characteristics of my Mk.1 ratchet engine.
In addition to that, it can't roll backwards, making it an excellent hill climber.
[Cheats a bit by thrusting itself into the ground; won't be doing that in refined versions]

To operate:
Keep tapping F.
Simple as that.