Forget Wii Remotes, Kinect, Move, and brain control: All we really need to play videogames are the electrical fields surrounding our eyes.
A group of engineers and self-described nerds from Austin, Texas that call themselves Waterloo Labs have developed a system to control Super Mario Bros. for the Nintendo Entertainment System that doesn't require the classic rectangular controller. Waterloo instead uses the movement of the human eye to navigate Mario through the dangers of the Mushroom Kingdom.
The accompanying video of their invention doesn't just show off the interesting tech, but it also makes me feel like I learned something. It turns out that the human eye is polarized and has a large population of neurons on the retina. As it moves, so do the the electrical fields surrounding it, which Waterloo measures with their electro-oculogram.
Placing electrodes on the left, right, top, and bottom of the eye will register either negative or positive signals. Waterloo connects these electrodes to a circuit board that filters the signals, and through a bunch of other hootenanny translates them into the controls for an NES console. Looking up will make Mario jump, while looking left or right will make him move in those directions. As smart as these folks are, they've overlooked the fact that it's hard to control a videogame character when you're not looking at the screen.
Regardless, Waterloo Labs also releases videos to explain how they do what they do if you want to make an attempt at it yourself. Just don't ignore the warning at the end of the video: If you don't ground yourself you could die playing Super Mario Bros. with your face.