This is coming. So fast.
It's not really tetris, it's so simplified as to be reduced to a simple press/ don't press action.
Also, the whole contraption is the union of two separate devices: an input device that picks up a single codified signal from an EEG (but could simply and more effectively track eye movements for the same result); and another one that produces a visible flick of light in a person's FOV- albeit not passing through the retina. That's it. It doesn't "transmit thoughts" at all, it transmits coded signals at a much slower rate than me typing on a keyboard right now.
Hooking up a portable BCI to a raspberry pi-equivalent as an intermediary should be all we need to really start connecting the brain electronically to the outside world in useful ways.
Despite my bs-filter having toned it down and given me just the facts that it's 3 people in a room with wires on their head playing tetris, with 2 looking at lightbulbs to send signals, it's still got me pumped.
I really believe BCIs be game changers in the way we communicate with electronics (if not other humans), and I for one would love to play a game of tetris over the internet with an unknown mind.
Edit: even in its current transmission rates, I think this tech could have far reaching implications in a better form factor. 1 slow bit is all I need to take a picture, lock/unlock my car, flip the light switch, turn the tap, open/close the door, Start the washing machine, turn the tv on, start the car, close the window, etc.