Algodoo

I reverse-engineered Paradigm29`s famous hovercraft (to which this is a response if you haven`t seen it and rated it five stars) and made my own simple hovercar. Paradigm took great care to make sure that his hover drive didn`t push the vehicle in either direction, but for this one the hover drive doubles as the forward propulsion. Not quite as complicated, but it also means that you don`t have to go messing with the .phn file to make a superfan to power it. It also gets very fast. The coolest thing about this method of propulsion is that it can not only handle rough terrain, but actually thrives on it, accelerating like a bat out of hell when it hits bumps.

ASD to control the hover drives, arrow keys for a weak directional controller that you probably won`t need to use. When you hit the zipline, just ride it. Running the motors will only slow you down.
Also, there`s an alternate path or two you can take. The spike pit can be driven over if you don`t fall onto it too hard and stick yourself, and it isn`t necessary to catch the zipline.

Oh yeah, and everything that`s white is zero-friction.