Still can't help but to think about Hetalia when I see this...
The Tower Spherical Engine.
Opposed Piston Engine: Apparently it can have better thermodynamic properties which leads to better fuel efficiency. There are a bunch of different tradeoffs with maintenance and engine size too, but it really depends on the specific applications
VWVortex.com - The Automotive GIF Thread
Brakeboard - Brakes For Longboard Skateboards. by Benjamin Newman — Kickstarter